According to court documents, she intended to become a nurse in an ISIS camp. She is a Colorado certified nurse's aide.
Here are three key questions about her case:
1. What does she say about her crime?
Conley seemed friendly and nervous Thursday, sometimes hesitant to say anything that would upset her attorney, who wasn't present.
She was happy to talk about less-sensitive matters such as her new coiffure: a tight braid to her dark brown hair, arranged in four or five rows. She wasn't wearing a Muslim headscarf.
"Oh, this is for tomorrow," Conley said about her new hairstyle for the sentencing in federal court.
She declined to go into detail, however, about her pending punishment, in which she is facing a maximum of five years in prison and a $250,000 fine. She pleaded guilty last year
to conspiring to provide material support to a designated foreign terrorist group.
"I'm in a vulnerable place right now, and it would be stupid of me to talk to you when I'm vulnerable," she told CNN during a video conference visit in the Jefferson County Detention Facility in Golden, which didn't allow any on-camera taping.
She didn't want to talk about her crime.
"No comment," she said. "Didn't you learn your lesson last time?"
That was a reference to CNN's prior jailhouse visit, in which Conley said her attorney had advised her against talking to the media about her case.
But Conley did acknowledge a measure of transformation since her arrest and jailing pending her sentence. That's why she changed her name, she said.
"I'm a different person than when I came in," she explained.
2. What does her family say about her?
Her mother, AnaMaria, was blunt.
"She was clueless. She's just a teenager, young, with a big mouth," the mother told CNN last year. "I think another time, another place, she would just be another kid with a big mouth."
ISIS is extremely savvy with its Internet propaganda, and her daughter was a victim of the jihadist group, AnaMaria Conley said. The mother worries about other impressionable young Americans.
"I hope that justice rather than fear will prevail," the mother said.
She and her husband, John, were aware of their daughter's conversion to Islam but didn't know about her interest in extreme Islam or jihad.
John Conley reportedly caught his daughter talking to her "suitor," a 32-year-old Tunisian man, on Skype. The couple asked for the father's blessing, but he said no.
On April 1, the father called the FBI to report that he had found her ticket for an April 8 flight to Turkey on his desk.
3. How much evidence do prosecutors have?
The FBI and Joint Terrorism Task Force were tipped off to Conley's suspicious activity in November 2013, when the pastor and security director of Faith Bible Chapel told local police that Conley was wandering around campus and taking notes, court papers said.
The church's main campus in Arvada was the scene of a gunman's fatal shooting in 2007.
When church staff confronted Conley about her notes, she allegedly told them: "Why is the church worried about a terrorist attack?" and that terrorists are "... not allowed to kill aging adults and little children," according to court papers.
Church officials asked her not to return.
In an interview with the FBI the following month, she said she joined the U.S. Army Explorers to receive military training and intended to use the firearm skills to go overseas to wage jihad, court papers said.
Over five months, authorities interviewed her seven times.
Conley told them that "jihad must be waged to protect Muslim nations," court papers said. She preferred to wage jihad overseas, to be with jihad fighters.
Conley told investigators she "would be defending Muslims on the Muslim homeland against people who are trying to kill them," according to court documents.
Conley told her parents that her knowledge of Islam was based solely on research she had conducted on the Internet.
Four days before Conley's April 8 flight, federal investigators again questioned her about whether she would engage in actual combat on the ISIS battlefield.
"If it was absolutely necessary, then yes. I wouldn't like it ... but I would do it," she told authorities, according to court papers.
But, she added about her ISIS suitor in Syria: "He's the man, he should be doing the fighting."