My girlfriend's mom is too nice!

(This was posted originally to r/relationships but I was told it would be more suited here..)TL;DR: My girlfriend's mom is too nice and its affecting the way her children are being raised.I (16f) have been dating my girlfriend (15f) for 2 years going on three. I love her mom, she's always gotten me food when I don't have any, she drives me home. And is overall a really sweet lady.The issue is she has 4 kids, and has no idea how to handle them.That's harsh, and I'll admit it's a bit over exaggerated.(Now some background info) She works with disabled people; they take up most of her time, one of her clients who suffers with bulimia and other mental disorders lives with them.She does everything around the house, she cooks, cleans etc.. her children I'll say, A, B, C, D. A is 19 years old, he lives in the garage. And all he does all day is play video games. Hes cool, we play DND together with B. (My girlfriend) but hes a selfish prick. He doesn't babysit for his mom, gets his mom to pay for his phone bill, Internet, He doesn't pay rent, and gets her to drive him to work mon-thurs every week, it's an hour ride in total everytime.B, As much as I love her. Gets her mom to drive her to school and back everyday. Which I get isnt that bad, but they live up on a hill. And she could go on a bus, and B has really bad anxiety and often misses school. Her mom never tells her to go, and has missed about 2 months of school last year.B is the nicest to her, she babysits her siblings, and was the only one to do something for her mom on mother's day.C is 11 years old, he has an attitude sometimes, hes really sweet and I can just see him struggling to get any attention, his siblings make fun of him and stuff.. while his youngest brother hogs all the attention.D, is 4 years old (Almost 5) and he is a nightmare. He screams constantly and is very aggressive, hitting his mom and siblings. He may have mental or a disability, but he's very attention hungry and always. Gets his way.B's mom is so nice, but she struggles to discipline her children in anyway, B didnt know how to Shower for a while, when we first started dating, she struggled on a basic way, and it really frustrates me that she wasn't taught basic life skills. She misses so much school and I worry about her future.B's mom has gotten them therapy and is good in diagnosing any issues there might be, but shes drowning in stress of everything around her.I fear for the future of her kids in general and want to help, But I really cant.. there's not much I can do.. this is more of a rant.. but any thoughts would be appreciated on this matter.. via /r/Parenting http://bit.ly/2XamTDm