Babysitting a neglected baby. Pls give advice

So basically I’m going to keep this on anon because I have no clue if anyone I know is on this. But here we go.. so my friend and I are both teens. She’s 17, I’m 19 and we are both parents. She had her baby at 16 and I had my baby about six months later. Well she’s always been a party girl and super full of drama. I’m very shy so I barely have friends. I am on maternity leave and she was going back to school so she asked me to watch her baby and I thought yeah it couldn’t be too hard. Well as soon as she drops her off, she screams. Non. Stop. If I open any door, including the fridge, she screams. If I grab a sweater/ coat, she screams. My baby barely ever cried so this is very weird to me. This girl obviously has attachment issues. When they bring her, I’ll go to change her diaper and there is shit on her butt!! They’ve obviously changed her but just don’t wipe her!! Her diaper is caked with dirt and sand. They don’t say I love you or even bye when dropping her off. They don’t leave her milk (even tho they know I don’t drink dairy) or even diapers and wipes. They bring her food to eat and it’s literally mr.noodles or Kraft dinner!! And I know she has money to buy actual food, she just spends it on weed or herself instead. Her daughter is about 15 months, my daughter is 9 months. I’ve been watching her for months but my daughter is walking now and it’s so hard. Mentally, I’ve been declining while dealing with this. I have post partum anxiety and depression so I’m really struggling. I try so hard to love up her daughter and feed her actual food while she’s here. This girl has literally left her in a jolly jumper for hours while she left her apartment to go get high with her neighbor. When she came back her daughters butt was bleeding. I’m just so sad. She deserves good parents but I also don’t want to hurt our friendship I guess. I’ve decided to stop watching her because every time she comes over she’s sick. So my daughter was non stop sick for months straight. It’s not worth my daughters health and my mental health but I really do feel bad for this girl. What should I do?

Edit: I have already called child services with my sister. They did nothing