My parents have had cat problems you would not believe. If she is doing most normal things normally it is probably okay. We had a cat who seemed to cough up a hairball every single day for fifteen years.

That said, the health of your animal is not trivial to your mental health. There is a lot to be said for animal therapy. I can't tell you how many times I held it together just because another creature was dependant on me. If anything happened to my bird, my next stop would be in-patient.

I was raised in Cat-land and as a former citizen of of Cat-land I am telling you that at ten years you getting close to facing the mortality of your companion. Normally I am against "replacement pets" but you might think about hedging your bets and bringing home a kitten sometime in the near future. Hopefully you get another five years with your cat but just in case you will already have someone else you have bonded with and will be there for you when you need them.