Little Miss finicky

My Little Miss Meowsalot takes being finicky to a new level. She once quit drinking for a couple months because I changed her water dish (she got moisture from wet food) if I change her wet food she will go a day without eating it (I feed her half wet and half dry in separate bowls) now she has decided the only wet flavors she will eat are the seafood ones. I've heard it's dangerous to feed her just seafood wet food. Is this true?

As long as the food is complete and balanced than she should be okay. Ideally, they eat a variety of things. Realistically, some food is better than no food and if she's eating it well, then go with it. The danger is if she's a one flavour wonder cat and she decides that's yucky, or the company changes the recipe or discontinues the flavour all together.

I have always heard and read that feeding a lot of seafood isn't good.  It's good that she is eating something, but I would continue to try to get her to eat other flavors as well.  

Eating too much seafood is risky because it contains more phosphorus, which can lead to UTI stones. Fish also contains mercury. Some kitties also get addicted to fish and will eat nothing else. You should feed fish once or twice a week.