I'm wondering about diabetes! Older cats are more prone to this condition than younger ones and your cat's symptoms certainly sound suspicious.

Excessive thirst is frequently a sign of diabetes (in animals as well as humans), as is increased urination. Incontinence may be a result of a bladder infection which often accompanies this ailment.

I think your cat needs checking out with a vet as soon as you can arange it.

I'm sure she'll be just fine but do get back to us when you know a bit more.