"Yes. Absolutely," Stiviano, 31, said when Walters asked her during an exclusive television interview in Los Angeles.
"I think he's highly more traumatized and hurt by the things that he said himself," she added. "I think he can't even believe or understand sometimes the thing he says, and I think he's hurt by it. He's hurting right now."
Asked if she thought he would go through with a public apology, Stiviano replied: "God only knows."
This is the first television interview for Stiviano since the NBA handed Sterling a lifetime ban and a $2.5 million fine on Tuesday for his racial remarks about African-Americans featured in a leaked audiotape recording.
Prior to this interview with ABC News, Stiviano had been seen in public wearing a large visor over her face, which she said made it "easier to mask the pain."
The interview comes a week after TMZ released the audio recordings, which subsequently launched the league investigation that led to NBA Commissioner Adam Silver to ban Sterling for life. The NBA Board of Governors will vote on whether or not Sterling will be forced to sell the team.