In a new interview, the Charlie's Angels star revealed that her mother worked as a stripper in order to support her family.
"She was 5ft 11, legs up to her ears, gorgeous," Kelly told Cosmopolitan. "She got along on that for as long as she could."
The actress, whose father is former Aerosmith guitarist Rick Dufay, went on to say that though her relationship with her mother was "pretty complicated", she was with her until the end.
"By the time she passed I was holding her," Kelly said. "I was with her until her last breath. We made it."
Kelly recently confirmed her split from boyfriend of three years and New York Yankee Derek Jeter.
The actress has reportedly grown close to Charlie Angels co-star Ramon Rodriguez in the wake of her break-up from Jeter.
Charlie's Angels premieres on September 22 at 8/7c on ABC.