Thank god there not from my mom.?

My father has 4 daughters. 3 by one lady and me 18 by my mother. My sisters are 30 with 6 kids, 29 with 2 kids, and 28 with 4 kids. The problem is with my sister who's 28 and has four kids. I don't understand why she lives the way she does. She lives very dirty in all the houses and apartments they lived in. They always had roaches and rats but got rid of them. Thank god!! She's home all day and don't clean well the kids are at school. When she could be scrubbing walls. Her children are boy 11, boy 6, boy 5, and girl 4. Her children are so disrespectful it's ridiculous. These are the worst bunch of kids i have ever seen. They use profanity all the time and when i look at her like your just gonna let them talk like that she's says oh they'll grow out of it. It's so sickening. She has money ever time she moves she always buys new bedroom sets and living rooms but i don't get why because her kids f**k up everything. Sometimes when i go over their im scarred because i never know what there going to do next. She lets her kids get so dirty. When she does hit them she hits them with flies water, spachelas, and whatevers in her sight that she can throw at them. She yells and yells and yells.When we go in public it's embarring because they don't know how to act. What can i do? I know if i stop going over there it will hurt her cause i'm the only person who she is really close to. But i cant stand these f**kin kids anymore. Even 911 nanny cant save these kids. My other sister 30 lives okay i guess in a two bedroom apartment with 6 kids but at least their not direspectful and are well behave and very much disciplined. My sister 29 with 2 kids just got a visit from cps (child protective services)for the first time and does drugs what will happen if the test comes back dirty. I really dont understand why they called on her she the cleaness out of them 3, kids well disciplined, and very respectable.