I am sorry to say that she is gone. Cancer took her life at the age of 15. I know 15 is kind of old for a cat, but other than the cancer, she was in great shape, and she had been a very happy cat.
One of my favorite things to do each morning would be to look for my coffee cup, which is white with little black cat silhouettes "walking" around the bottom edge. And each morning when the coffee was ready, I would walk into the kitchen and say, "Where's my cup?" And Buttercup would let out a little squeaky MEOW. I would look at her and say, "There's my Cup." And of course, I would continue looking for my "other" kitty cat cup too.
I will miss her forever.