Update on my sons friend

My sins friend has been stay with us. His mom abandoned him at home and she is pretty neglectful. Her son is 11 and still wears pull ups during the day and night. She wouldn't answer my phone when her son was freaking out at the sleepover. Sent some man he didn't even know to get him and dragged him by his shirt yelling at him when she picked him up. For the 4th she abandoned him again with nothing but a large bag of cereal to survive on.... He's in my custody and mom hasn't checked on him once. I went on her Facebook and she posted a picture of her partying and titled it 'Freedom'....

So how he is. He no longer wear pull ups during the day. I just sent Timex for him to go to the bathroom to avoid an accident. Night time though... Accidents. I'm waiting for his bed to arrive, until it does he and my son share a bed and if his pull up leaks through my son takes his sheets to the laundry room and doesn't mention. I've talked to him about life with his mom. He says she just has a bad temper and can hurt him sometimes nut its because he's bad. He said he did a bad thing and his moms friend touched him inappropriately.... Its all so sad... But he'd adjusting well. We are working on his eating because he eats his food very sparingly and saves the rest even though I can tell he's still hungry. I told him there's plenty of food and he can eat as much as he wants. Besides that and a few hiccups he's ok.

Edit: I'm not quite sure how what's going about about making it permanent because they are trying to find his father. I'm fostering him right now. Whatever happens I just want him to be safe.