The wounded congresswoman could hear the clapping from people who crowded on the sidewalks and waved "Get well soon" signs as the ambulance carrying her made its way slowly through the streets of Tucson. And she understood that it was for her.
"She responded very well to that, smiling and in fact even tearing up a little bit," Dr. Randall Friese, who accompanied her on the journey, told reporters this afternoon.
"It was very heart-wrenching. It was so wonderful to see the support that Tucsonians and Arizonans have for Gabby. We love her."
Giffords' husband, astronaut Mark Kelly; her mother, Gloria; Friese and trauma surgeon Peter Rhee; nurse Tracy Colbert; and two congressional staffers accompanied her on the two-hour flight to Houston.
She was taken first to the University of Texas Health Science Center for evaluation, and will eventually be transferred to the TIRR Memorial Hermann Hospital for rehabilitation.
The Houston rehabilitation facility is close to where her husband plans to resume training to command a NASA space shuttle mission this spring.
Friese said the journey "went flawlessly." Giffords spent the flight napping and interacting with her mother and husband, he said.
Trauma experts at the Texas hospital said they were very pleased at the condition of the Arizona Democrat, who was shot through the head on Jan. 8 at a meet-and-greet session in a Tucson supermarket parking lot. Six other people were killed.
"She looks spectacular," said Dr. Dong Kim. "She came into the ICU, she was alert, awake."
Doctors said Giffords would stay in the hospital's intensive care unit for a while before moving to the Hermann facility, but she will begin rehab immediately.
Her caregivers will watch carefully to make sure she does not develop any sign of infection in the drain in her skull. Doctors removed part of her cranium after the shooting and it has not been replaced yet. She has a special helmet -- decorated with the Arizona flag, because Kelly said that was what his wife would want -- to protect her exposed brain, doctors said.
"She knows what's going on," Friese said. "There's no question that she's aware of what's happening."
"She has great rehabilitation potential," said Dr. Gerardo Francisco, chief medical officer at TIRR Memorial Hermann.
Giffords' aides said they were overwhelmed with people asking to see the congresswoman off outside the Tucson hospital today. "People want to line the route. People are calling. They're saying, 'Where can we stand?' " her communications director, C.J. Karamargin, told the Arizona Daily Star late Thursday evening. "Gabby would love the show of support."
Thursday night, the well-wishers gathered outside University Medical Center in Tucson, knowing it would likely be the congresswoman's last night in her home district for at least a few months.
"We just wanted to show our support to all the people that this happened to, the tragedy," Tucson resident Hannah Greene told KOLD-TV, standing outside the hospital.
"We kind of felt it might be the last night, too, that Gabrielle Giffords might be here, and thought that maybe if her family was looking out the window, they'd still see all the people that are still coming," Hannah's mother, Jill Greene, told the station.
Earlier today, the ambulance was escorted by police as well as a pack of motorcyclists from the local chapter of the Veterans of Foreign Wars, many of whom were acquainted with Giffords. The Democratic lawmaker rode with the group in May 2009 when it escorted the remains of Civil War-era veterans from Tucson to Sierra Vista, Ariz.
The team of doctors who will work with Giffords in Houston told reporters this afternoon that the congresswoman has "very good movement on the left side of her body," but it is unclear how much strength she has on the right side. The bullet went through the left side of her brain, which controls movement in the right side of the body.
She is able to move her lips, although it's not clear whether she is mouthing words. Doctors are also not sure how much she is able to see.
Meanwhile, the 22-year-old accused of killing six people during the attempt on Giffords' life is set to appear in a federal court in Phoenix again on Monday. Jared Loughner has been charged with murder, and even more charges are expected.
His federal trial is expected to be moved to San Diego, where the judge assigned to the case is based, as well as his lawyer. The change of venue was necessary because one of those killed Jan. 8 was a federal judge, John Roll, and most of Arizona's other judges have recused themselves from the case because they knew him. Also, the entire community of Tucson is traumatized, and it would likely prove difficult to find an unbiased jury there.