Her children True and Lillie Parker shared the news on Dec. 5, writing in a statement posted to her Twitter page, "We are sad to inform you that our incredible, fierce and loving mother has passed away after a battle with cancer, only recently discovered."
Kirstie was "surrounded by her closest family and fought with great strength, leaving us with a certainty of her never-ending joy of living and whatever adventures lie ahead," her children wrote. "As iconic as she was on screen, she was an even more amazing mother and grandmother."
After thanking the staff at Moffitt Cancer Center in Florida for their care, True and Lillie reflected on Kirstie's legacy.
"Our mother's zest and passion for life, her children, grandchildren and her many animals, not to mention her eternal joy of creating," they said, "were unparalleled and leave us inspiring to live life to the fullest just as she did."
Kirstie had her breakout role playing Rebecca Howe in NBC's Cheers from 1987 to 1993, which won her an Emmy and Golden Globe Award.
Over her career, she became known for her roles in Veronica's Closet, Look Who's Talking, It Takes Two, Drop Dead Gorgeous, Scream Queens and more.
As for her personal life, she was married to Bob Alley from 1970 to 1977 and actor Parker Stevenson from 1983 to 1997, adopting children Lillie, 28, and True, 30.
According to the actress, she became a "single mother" when her kids were 3 and 6 years old.
Becoming a grandmother years later was one of the highlights of her life. "Being a grandma is in the top three best things that has ever happened to me," she told People in 2016. "Friends used to show pictures of their grandkids and I'd be like, 'Yeah yeah they're [cute]' or 'whatever.' Now I'm totally that grandmother."
In addition to her family, the Art of Men author also had a strong bond with her Look Who's Talking co-star John Travolta, saying in 2018, "I almost ran off and married John... I did love him. I still love him. If I hadn't [have] been married, I would have gone and married him."
It's clear the pair were close. Following her death, John posted a photo of the actress and wrote, "Kirstie was one of the most special relationships I've ever had. I love you Kirstie. I know we will see each other again."
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