Strange crocodile dream?

Water is a symbol of emotions; a crocodile in waking life is a predator; but there is also a phrase about crying "crocodile tears" which means false sentiments or fake tears. Your gf may have liked drama in the past, and she may have cried false tears or made up issues/lies, but it seems she has matured more, and does not want to go back to her old ways. There may also be issues in her past she wants to forget. So she does not want to bring that crocodile back to life.