I remember years ago when that happened to My BJ , who showed no signs of illness and was fairly young at 10.
He just collapsed and died on the bed as I was calling My Vet.

It sounds as though Taffy may have had heart troubles with stomach problems that kept her from being able to digest her food.
Taffy still loves you and wants you not to be sad, but to remember the good times and to think of her spirit which will always be with you,
and maybe one day you will see a Cat who needs a home, and Taffy would be pleased if you adopted that Cat in her honor.
And Taffys with the Animal Angels now and will find a place for her beloved Family to be together again in love.
One Fine Day!