My dog always eats the cat food...?

Alright, my ex boyfriend gave me his dog and when she lived with him she always ate dog food(they have a cat too, so there was cat food there.) and now that she lives with me she eats nothing but cat food, she will NOT eat dog food...she's an adult, so can she get as sick as if she were a puppy eating nothing but cat food? Because I know that dogs who eat cat food their whole life end up having problems in the future, will that still happen even though my dog is an adult? Oh, we've tried mixing wet dog food into her food..and just plain wet dog food, she won't eat it no matter what we do. We even put beef broth in it. So my questions are, is there anything else I can do? And will she get sick?! D: