According to the news source, Giffords surprised colleagues by showing up to cast her vote for the debt-limit bill on Monday night.
Democratic leader Nancy Pelosi of California told the House, "It means so much to our country ... to witness the return of our colleague who is the personification of courage, of sincerity, of admiration throughout the country."
Giffords, a congresswoman from Arizona, was shot in Tucson where she was conducting a meeting. Six people were killed including a nine-year-old girl and 14 injured.
Jared Lee Loughner was charged in the shooting and sent to a prison mental hospital after being deemed mentally incompetent to stand trial.