Should I give up on this book idea?

Well, you make the decision on WHO you are going to write for. Either if it's for children or adults. You choose, but I don't want you to stop writing. The story can be interesting and fun, and I feel that it can relate very well to the children since it's like some fantasy novel. Just choose your audience first then start writing. If it's for the children, you can still have the part where the cat's boyfriend (^.^) to save the daughter of the cat leader and have a happy ending. If it's for adults, you could put the struggles that the cat boyfriend had to save the other. Maybe even put kind of an eccentric characters along the way, maybe even a secret that you can say that humans don't know that animals can really talk because of this and that. Good Luck and don't give up! This can be inspirations for a lot of writers to come. :)