I've had my Chins for a year and a half. When I got them it was mom and her 6 day old baby. I'm 99.9% sure the baby is a male as was the person who had them-he used to breed them and someone dropped them off at his house. Anywho, I've tried weaning them 4 times. I tried right off the bat twice in my house, and twice more within the last year at my mom's house, but the female stops eating every time, the last time was for 2 months. The last time was really bad, I spoke with the vet because her system totally shut down from not eating for so long. They weren't experienced with chins so it wasn't a lot of help, but they said put her back in with the son and see if she got any better. They said I could bring her in, but I didn't really trust letting them experiment on her. Her stool was rancid and runny when she first started eating again, but she got better. She was skin and bones, but she's doing a lot better now, still not round and plump though.
Long story short, the vet said to just give it up and leave her with her baby. Her baby could care less about ever seeing her again, but she "cries" all night and won't eat without him. I have even tried putting their cages next to each other. I spoke with a breeder about it as well and they said it's not great if she gets pregnant by him, but most likely there won't be issues unless I keep inbreeding, which I do not want to do. I don't want them to breed, but I don't want her to die either. She has had a rough life, she is missing a bunch of toes, has a broken tail, and she won't let us touch her for anything. I'm pretty much throwing in the towel on separating them. I don't have another female for her to hang out with, I don't know if that would help, I'm totally out of ideas!!! I've even thought about getting a female for her to "befriend" then take her son out, but then I have the chance of two females getting pregnant.