Do you think I should make my little sisters rehome her aggressive dog?
why do you want to rehome your sister's dog?
I don't want to deal with her shit anymore.
Your sister owns a dog so let her decide what to do wiith it. If you have problem with dog's behavior, tell her that to her. You cannot make decisions for her pet.
I don't want her to keep the dog.
I suppose you can express your concerns, but it is ultimately your sister's decision and you need to respect that.