I'd definitely get a second opinion. I adopted a 14 year old cat, Murphy, in December and she had thyroid problems that were corrected by the Humane Society before I adopted her. I've noticed that she vomits whenever I give her anything other than dry food. Since she's been on nothing but Wilderness Cat food, a high quality, expensive dry food. The vomiting has all but disappeared.

Since your precious baby has been through so much with her cancer and stuff, do the best you can for her. You guys will be in my thoughts and prayers.