(CNN) -- U.S. Rep. Gabrielle Giffords is recovering "really, really well" from surgery that implanted a synthetic bone and a shunt in her skull, her doctors said Thursday.
The Arizona Democrat told her neurosurgeon that she was extremely excited to have crossed a key milestone in her recovery, which her doctors called "almost miraculous" considering she was shot point-blank in the head in January.
"The shunt is in good position, the implant is in good position and everything looks great," said Dr. Dong Kim, who performed the 3 1/2 hour-surgery to replace the part of her skull bone that was shattered and contaminated.
"She looks great," he said. "I started calling her 'Gorgeous Gaby' today."
The shunt is expected to help Giffords improve but, Kim said, it was impossible to predict exactly how much progress she was going to make.
The Arizona Democrat was shot outside a Tucson, Arizona, supermarket where she was meeting with constituents in January. Six people -- including a federal judge -- were killed and 13 others were wounded in the attack.
Jared Lee Loughner stands accused in the shooting.
Surgeons in Arizona had cut a hole in Giffords' skull to give her brain space to temporarily swell. The congresswoman was later transported to Houston for further treatment and rehabilitation.
Her skull could be repaired only after the swelling had subsided. Kim implanted a piece of synthetic bone specially made for the congresswoman.
"It really is a significant step. More than just getting the bone back, it is a marker for where we are" in Giffords' recovery, Kim said.
Like many other patients with gunshot wounds to the head, Giffords has hydrocephalus, or a build-up of fluid in the brain.
Kim said an internal drain, called a shunt, was inserted into Giffords' cranial cavity to carry excess fluids from the brain to the abdominal cavity. Giffords will have to wear the shunt forever.
Dr. Girard Francisco, who is in charge of Giffords' rehabilitation, said that the congresswoman will undergo bedside rehab for at least the next two days before returning to the in-patient program at the TIRR Memorial Hermann Rehabilitation Center in Houston.
Giffords' husband, Mark Kelly, the commander of the space shuttle Endeavor, has been getting updates from conversations with family.
"Everything went as planned," he told PBS Thursday from the International Space Station. "Her neurosurgeons are very happy and she's recuperating and she's actually getting back to therapy today so it went really, really well."
Monday, Giffords watched and cheered as the Endeavour took off on its final voyage from the Kennedy Space Center in Florida.
CNN's Elizabeth Cohen contributed to this report.