Over there, she points, is Fort Johnson, the place on James Island where a warning shot fired by Confederates toward Fort Sumter unleashed the Civil War. She pictures what it must have felt like to live here then.
"Imagine this harbor full of ships, fighting day and night. It was going crazy," she says. "Maybe people thought of it as entertainment, if they weren't running for their lives."
She turns to the left, her camera phone at the ready, toward the place we're headed: Fort Sumter, a must-visit for history buffs and a place this native Charlestonian has never seen.
"I think this is where people are real mad that the [Confederate] flag's down," she says.
From the six flagpoles on the horizon, only one flag waves today: the Stars and Stripes. The others, representing the timeline of who held this garrison, are all under federal review, part of the cascading change that has washed over this region and the nation after nine African-American churchgoers were killed in Charleston. A white man, who glorified the Confederate flag, is accused of shooting them.
The June 17 tragedy was personal for Tre'anna. She counted the youngest victim as a friend, a brother. And the conversations that followed stoked a feeling she's felt since she was little -- a hunger to know history, especially her own.
"I want to be an Alex Haley and find my roots," she says.
But she's never been to the plantation near her home or to Fort Sumter, places that helped define our nation, shaped this city's history and, in many respects, made this girl who she is. She represents the generation for whom recent events will matter most, so I invite her to visit those sites with me. I'm an outsider looking in, and I want to see Charleston through Tre'anna's eyes. Along the way she will help open mine.
'I forgive them'
We first meet in front of the growing memorial that lines the front of Emanuel AME Church, or Mother Emanuel as it's affectionately known.
She marvels at the steady flow of visitors who stream by, paying their respects weeks after the tragedy at the church and hours after the Confederate flag came down
at the South Carolina Capitol.
Thrown into the national spotlight, her city makes her proud. Tre'anna boasts about its response to violence. People here weathered the April police shooting of Walter Scott unscathed -- "We weren't like Baltimore, burning down our city," Tre'anna says. And they're emerging from the June Bible study massacre stronger.
Thousands joined hands across the Ravenel Bridge to show their support for Mother Emanuel.
That said, she's unfriended some people on Facebook as arguments about the Confederate flag took over. They seemed to care more about that flag than they did the lives lost, she says. Steeped in grief, she didn't have it in her to debate history.
"I'm not mad. I forgive them," she says. "But it shows they don't care."
And it indicates that they don't get what that flag symbolizes for her and her people.
We were called "human property," she says. "I have an iPhone. That's property."
She slips her iPhone from her pocket. She wants me to know her friend who died in the shooting, 26-year-old Tywanza Sanders. He was her older brothers' best friend. He called Tre'anna's mother "Mama Shaw." Tre'anna plays videos of him singing and reciting his poetry. His big smile shines from her Facebook cover photo. He tried to reason with the gunman before he was shot. He took a bullet trying to protect his aunt, who was also killed.
"You're a hero," Tre'anna scrawls on the memorial ribbon that bears his name outside the church. "I love you, and I'm going to miss you."
She thinks about the kids who wear Confederate flag T-shirts at her high school and wonders how many of them, come fall, will pull into the parking lot with flags flying from their trucks.
"Stop listening to your parents," she wants to tell them. "Do your own research."
A Gullah woman
She was only 3 when she began eyeing the McLeod Plantation on James Island, not far from where she lives. She could see it whenever the family car crossed the Wappoo Creek Bridge. She peppered those around her with questions.
"What are those little houses?" she asked her mother.
"That's where the slaves lived."
She'd look at the water surrounding this mysterious property and guessed that slaves didn't know how to swim. Or maybe, she reasoned, they were told alligators swam in those waters and would eat them if they tried to get away.
Now, just months after the historic site opened for visitors, she walks toward the welcome center so she can see it up close.
"Fresh from Africa, they were given new names. They had names that meant 'strength' and 'courage;' what's 'Toby' to them?" she says. "They didn't speak the language, and they were scared."
The McLeod Plantation, one of at least 17 plantations that once sat on James Island, according to our guide, tells the story from the perspective of the majority population that lived here. It honors the Gullah Geechee culture developed by enslaved Africans living in the Lowcountry and often isolated on islands.
Our guide talks about the genesis of the Gullah Geechee language, a creole language blending influences from different West African nations. She rattles off the pronunciation of words for which people later were made, by outsiders, to feel ashamed. Words like "this" came out as "dis," and "strawberry" might have come out as "scrawberry."
"Do you know people who sound like that?" the guide asks our group, Tre'anna being the only black visitor among us.
"Me," Tre'anna answers.
"OK, you're a Gullah woman!" the guide, Sara Daise, says with a smile. She's one, too. And she tells us later that she's especially happy to see Tre'anna's face because not many blacks visit the plantation.
Daise talks about how the enslaved workers taught one another their new and common language, and shared tips about what could be eaten or used for healing. They were often sold separately from their children, so the children who were around were every adult's responsibility.
"It takes a village," Daise, 25, says. "That's an African idea that developed on plantations as a means of survival."
Though the McLeod Plantation doesn't like the word slave -- those who work there prefer enslaved people or enslaved workers -- we walk along what was known as "slave street" or "slave row," where some of their cabins remain.
Each held at least 10 people, and inside they clung to their culture and flavors -- cooking with foods grown in the small gardens they kept and with shrimp or animals they caught to supplement what the McLeods rationed for them.
They worked 10 to 12 hours a day, often in oppressive heat, picking or sorting Sea Island cotton. Tre'anna peeks inside a cabin, wondering how hot it must have been back then, especially if they had to cook in this small room, too. Daise asks for examples of Gullah foods, and Tre'anna is the first to chime in: "Shrimp and grits!"
Daise turns to the songs enslaved people often sang. When she begins singing the spiritual "Mary Had a Baby," Tre'anna sings along quietly.
Mary had a baby. Aye, Lord. Mary had a baby. Aye, my Lord. Mary had a baby. Aye, Lord. The people keep a-coming but the train done gone.
People heard enslaved workers sing and thought, "Oh, they just love picking cotton," Daise says with a laugh. "But they were resisting. They were organizing."
The hidden message in this song referred to the Freedom Train, or the Underground Railroad. It was a warning to turn around and go back. Either people had missed the train or the mission had been aborted, the guide says, but those enslaved were looking out for each other.
"The Gullah Geechee people were not afraid to die, but that doesn't mean they wanted to," Daise says. "They wanted to live."
Before we leave, Tre'anna has a question.
"What do you have to do to get a job here?" she asks.
She's not old enough or educated enough to jump into giving tours; she knows that. But Daise says she's on the right track.
"We need people of color who are passionate about our history," the guide answers.
She then takes Tre'anna's phone number as the two walk on, bemoaning how they each need to learn to weave seagrass baskets, just as their ancestors did.
Near Tre'anna's home, our history tour takes a turn I didn't expect. She lives on Sol Legare, which is part of James Island but is an island unto itself. It is named for Solomon Legare, a slave owner who once owned this land.
After the Civil War, the area was divided and sold to freed slaves. Many of their descendants still call it home and most are related, Tre'anna says. They farmed the land and marshes, growing corn, watermelon and butter beans and catching crabs, oysters and shrimp.
The old family home was lost in Hurricane Hugo in 1989, years before Tre'anna was born. Her father died when she was young, and her older brothers are grown and gone. Tre'anna, her mother and two uncles now live in a modular house propped up high in this flood zone.
Right down the road is a piece of history that no storm could destroy.
"She stands proud," Tre'anna says.
The Seashore Farmer's Lodge is not the sort of place a typical tourist to Charleston would stumble upon. The small and unassuming museum, which is on the national register of historic places, celebrates the history and culture of those who live here. It was the community center for the freed blacks who settled on Sol Legare and included freed workers from McLeod Plantation. This center was their school, their church, their meetinghouse, their bank, their funeral home and more.
And this is where Tre'anna works as an intern, when she's not at school or playing basketball.
The lodge was restored in 2009, and she began hanging around as soon as the process started.
"I would give tours and she'd be on my tail asking questions," says Ernest Parks, 59, the curator and her cousin.
The two begin my education with a demonstration of funeral practices. Parks lies down on the couch, as if he's in a coffin, and explains how a saucer would have been on his chest to collect donations to cover his burial. They then talk about the continued practice of taking the youngest child in a family and passing that child over the dead to instill faith in the living and remove evil spirits from the deceased.
"I was passed over my grandmother," Tre'anna says. "Even though she had no evil spirits."
Around them are artifacts culled from people's attics and yards, including an 1862 rusted Confederate sword picked up off someone's land. Blues music by Robert Johnson, from the 1930s, fills the room.
A large diorama depicts a battle fought by the 54th Massachusetts Volunteer Infantry Regiment, the first unit in the Union Army to be comprised almost entirely of free blacks from the North. The 54th fought its first battle on Sol Legare.
Tre'anna peers into the glass protecting the scene and points to Col. Robert Shaw, the white man who led this regiment, the figure who was played by Matthew Broderick in the 1989 award-winning film "Glory."
Given the colonel's last name, she can't help but wonder if they might be related. Someday, she says, she'll find her answer. Weirder things have been proven true, she adds.
She takes me to a corner, where a model of a Ku Klux Klansman holds a noose with an effigy of the man he's hanged. Resting on a table in front of that is a branch of cotton.
"In our museum, you can touch the artifacts," she says. "You're free."
She picks up the branch, starts pulling the white fluff apart and invites me to do the same. She wants me to understand that what her people were forced to do was no easy task: "Be careful because it'll stick you," she says. And it does.
Her cousin, the curator, watches. He took notice of Tre'anna when she showed up years ago, and he still does.
"As elders, we start the process and let the next generation take it to the next level," he says, before turning to Tre'anna, who can't wait to pursue a degree in history. "You're going to take over this place when I'm gone."
Where Charleston, the South, the country will be when she does, nobody can say.
Will visitors still line up to honor those who were killed, including her friend, or will they have been forgotten? Will Charlestonians, white and black, continue to join hands? Will there still be those who care more about flags than they do human beings?
No one can know these answers. But Tre'anna will certainly be watching to find out.