Maybe you keep having the dreams because you’re scared something will happen to her, and you think, “I don’t want to dream about this” when you’re going to bed. Then you end up worrying about it and dreaming about it again. I suggest you think about something else during bedtime. Not that that’s necessarily an easy thing to do. You could also try to lucid dream, I guess. Of course, if you never think about this during the day or during bedtime, it just pops up in your dreams, I don’t know how to help besides lucid dreaming.