Dream About Bratty Niece

I don't really remember most of the dream. Mostly I just remember that my niece was there, but behaving very out of the ordinary. Much brattier, mean spirited. Very much not "her" even if she was in a bratty mood. She almost seemed a little older too, but I'm not sure tbh. We were in my step dad's old house, one he no longer lives in, and a house that my niece has never been in. Everything felt warm and safe, like relaxing on a lazy weekend night. Near the end of the dream, and what woke me up was that I was trying to sleep on my stomach on the couch (in the dream) and she was half on top of me, laying over my back and watching the TV. I guess I was tired of it, or thinking it was getting late for her so I grabbed the remote and turned it off, saying it was bedtime. The look she gave me was so cold, it was like it wasn't her face at all. And honestly looking back I'm not 100% sure it was really her face, and it doesn't help that both of us look so similar my family mixes up our names so now I'm just like. Was that a younger version of me? Not only that but I remember she said something, and just that it was cold, mean, and not something a 5 year old would say. I don't remember exactly what it was but I think it was something to the effect of "You're not worth as much as you think you are" And her eyes turned completely black! Pitch black like a demons.