Trying to protect her fragile state, staff and family members didn't let her know that six had perished in the Jan. 8 attack, including one of her most trusted staff members and a federal judge who was a close friend.
Just weeks ago, Giffords found out the truth, delaying a grief process the rest of the country had gone through months before.
On Saturday, a Giffords' staffer confirmed that the Democratic politician was told by her husband in late July that those who passed away included her close aide Gabe Zimmerman; U.S. District Judge John Roll, a close friend; and 9-year-old Christina-Taylor Green. The Arizona Republic first reported those details early Saturday.
News of who the victims were came to Giffords just days before her surprise Aug. 1 appearance on Capitol Hill to vote on the federal debt ceiling. Her loved ones had been keeping the scope of the tragedy from her until she was strong enough to handle it.
"She knew for some time that six people had died and 13 were injured, including herself," said Mark Kimble, who is Giffords' new spokesman. "In late July, shortly before she went to Washington, she wanted to know more information, specifically about who had died. That's when her husband told her."
According to Kimble, only Giffords and her husband, newly retired astronaut Mark Kelly, were in the room when the congresswoman learned of the names of the six who died.
Later, Giffords gave her personal condolences to Zimmerman's father during a brief telephone conversation on Aug. 7, the Republic reported Saturday.
"It wasn't very long, but it covered important things," Ross Zimmerman told the newspaper. "She said she felt awful about Gabe."
The man charged in the rampage in Tucson, Jared Lee Loughner, has been at a federal prison facility in Springfield, Mo., since late May after a federal judge concluded he was mentally incompetent to stand trial. Loughner, 22, has pleaded not guilty to 49 charges. Mental health experts have determined he suffers from schizophrenia.
Meanwhile, the return of Giffords to Washington to cast a vote on debt-ceiling legislation fueled speculation about whether she'll seek re-election next year or run for a U.S. Senate seat.
Giffords, 41, hasn't yet publicly revealed her plans for the future. She has been undergoing physical, occupational and speech therapy in Houston as part of her rehabilitation.
Ross Zimmerman recalled from his recent phone conversation with Giffords that "she still has some trouble with language, but there is no question that she can get her point across and her comprehension is 100 percent.
"When she gets excited or stressed, it's harder for her to put words together in sentences," Zimmerman told the Republic. "That's the thing that she has the most trouble with. She's having to relearn language, and that's tough. She's having to learn how to write with her left hand at this point. And now, she's having to start the grieving process that the rest of us started back in January."