Selfish sister (long)

Asia
I just have to rant, so my sister is famous for always leaving her kids with anyone for days. Well after I got sick of it because Im almost due and she has 4 kids all under the age of 10, its just too much. So now she has been pawning them off on my dad, who has bad stress and anxiety on top of his bad healthy issues.. She just doesn't care, her kids aren't disciplined because she never sees them! She always says she will get them at a certain time she always shows up hours later. My dad can't say no because those are his grandkids and she has been known for keeping her kids away when shes mad. She doesn't help out and by food and expects you just drop everything, my dad is sick of it because he always talks to me about it but he can't put his foot down, & the kids fathers (four different guys) see them more then she does and shes the one who has custody if that tells you anything!! I love my neices and nephew but its just so ridiculous, shes not the perfect parent she claims to be. Shes in a different guys bed EVERY WEEKEND while the kids are with my dad or whoever else she can get to watch them! Ugh, why can't she grow up and be a mother?!😡😡 and then she wants to complain about not seeing them. Lol