Tell and the whole house will come falling dowm

My uncle is cheating on my aunt and bring the girl to our house and no adult in our family tells her because they don't like my aunt and talks shit behind her back and smile in her face while she lets them stay at her home for free. They always talking about how our house is dirty and this and that but stays here. There the only ones eating up our food while we don't eat and have to go out and eat. Plus there my uncles family (his brother, sister,mom) . I'm about to tell everything because I'm really getting tired of it. But I know she will kick them out and I don't want to see anyone out on the streets Should I or just let it go