I know pretty much nothing about animals, but when a person is sick, they're pretty much only going to eat what they're capable of. Something that is 'too much' for them won't seem appetizing because the body knows what it can and can't tolerate it.

If she's eating it, and it's sitting well afterwards, I say up the amount you give her and adjust to what she's wanting/tolerating. You might also check with your vet's office to see if they have any advice.