Welcome to Pet Talk! This is a great place for learning and encouragement.

I concur w/Karen: a vet visit is in order. It sounds as though she could be having dental issues and it's important to have a vet check it out b/c bad teeth can cause other health problems as well. Getting her spayed is vital, not just b/c she could get pregnant (hopefully, you've made her an indoor cat; much safer) but it can help to prevent uterine cancer.

Give your kitty some scritchies for me and please update us soon.