Does anyone else have nightmares about family? Because at least once a week I'll dream about robbers invading the house and raping my sister. Or my mom or my grandma dying. I keep worrying that something bad is going to happen. It doesn't help that my family is very stubborn and doesn't like to go to the doctor. (My relatives are older and have a history of falling and breast cancer.) I feel so nauseous thinking about it.
Everyone has nightmares. They are just dreams so you don't need to worry.
My recent nightmare was where it was pitch black in the parking lot at work and there was wolves lurking in the darkness and I had to go collect carts.
Your mind is trying to wrestle with something- but it can't just say "you're having problems with _____ on a subconscious level". Dreams are typically more about significance than they are about the actual events that occur in them. The one with your sister might indicate that you feel like she's being taken away from you or taken advantage of in some way- but because your brain is using the imagery it knows, it like- goes about it by trying to make symbols of things.
Idk if that makes sense. But I've had enough terrible dreams- like, I'll be talking to someone and someone else will come along and shoot them in the face, or just other heinous crap. I've even had dreams about having sex with people I wouldn't touch in a million years.
Point is, just because the imagery might be scary or gross, your brain is trying to solve a problem by using references. I'd try to cut down on any horror shows or news stories, if you can. And if all else fails, hypnotherapy and hypnosis are always valid options.
I get nightmares more often than I'd like to but they rarely involve my family. Everyone gets them sometimes, it's probably nothing to worry about. I used to get them every week like you but now it's more like I'll get one once every few months. I hated getting them so often but try to remember that they're just dreams. Your mind trying to make sense of what's going on in your life and sometimes it does so in really odd ways. How long has this been going on?
ocelot is 100% correct. your subconscious is worried about something, trying to figure something out, trying to tell you something, etc. its manifesting in the form of nightmares, but theres not a terrible amount you can do to stop it.
ive had nightmares every night since i was 12 years old (10 years now). they arent vivid tho, so thats good on my part. for you, i would try maybe some meditation before bed, or other relaxing things like that. it may help calm down your subconscious. i really hope they stop soon for you ):