It doesn't seem to bother Cats when they lose their teeth. Next time you are at the Vets ask him or her to check your Cat's teeth but in the meantime just feed her standard wet food .. tins pouches etc.
Hey.........I have the same 'problem' with my 15 year old Kit, we find that crushing the tablet into a fine powder and mixing it with yoghurt works really well as it's more of a treat, if it's a really 'bitter' pill then maybe sardines or something similar works better as it covers the taste. She seems to manage just fine with practically no teeth now, as long as any food is mushed up, she just gums it!!!! good luck xxxxxxxxxxxxx