In their statement confirming the news on Monday, Alley's children, True and Lillie Parker, said their "incredible, fierce and loving mother" had "only recently discovered" the cancer.
Prior to her untimely death, she was receiving treatment at Moffitt Cancer Center in Tampa, Florida.
" Surrounded by her closest family, she fought with courage, leaving us with a sense of her never-ending joy of living.
In their statement, they said she was an even better mother and grandmother than she was on screen.
Their mother's zest for life, her children, grandchildren, and many animals, not to mention her endless joy of creating, inspired them to live life to the fullest just as she did."