Rep. Gabrielle Giffords can walk while holding onto a cart, mouth the lyrics to easy songs, and have simple conversations, according to family, staff, and her doctors.

Mark Kelly said in an interview broadcast Monday on NBC that he can ask his wife questions and she can respond.

Kelly said she is trying so hard that her speech therapist, who only a few days ago was trying to get her to talk more, is now asking Giffords to slow down and make sure she hears the question before giving an answer.

The New York Times, citing doctors and her staff, reported on its website late Sunday that Giffords’ efforts to relearn how to speak have included mouthing song lyrics, such as “Twinkle, Twinkle, Little Star” and “Happy Birthday to You,” as friends and family sang along.

She has also been receiving bedside briefings from aides on the recent uprising in Egypt and on last week’s decision by Republican Sen. Jon Kyl of Arizona not to seek reelection. Her chief of staff, Pia Carusone, said “she definitely understands what we’re saying and she’s verbalizing.”

Giffords was shot in the head Jan. 8 while meeting with constituents outside a Tucson grocery store. Six people, including a 9-year-old girl and a federal judge, were killed in the attack, and 13 others, including Giffords, were wounded.

The congresswoman began intensive rehabilitation at TIRR Memorial Hermann in Houston late last month. The Times reported that an email sent to friends about a week ago by Giffords’ mother said that Giffords has been doing squats and repetitive motions to build her muscles and walking through the hospital’s halls while holding onto a cart.

The 40-year-old Giffords has beaten one of her nurses at tic-tac-toe and has changed from “kind of a limp noodle” to someone who is “alert, sits up straight with good posture,” the email from Gloria Giffords said.

Rehabilitation specialists say brain injury patients who regain speech typically begin to do so about four to six weeks after the incident.

The Associated Press contributed to this report.