Mollie was a stray cat, cautious around people but used to me. She had her kittens wild and I knew when she had given birth but thought the kittens hadn't made it since she still hung around just as much. 9 weeks later she showed up on my doorstep with three kittens. She was an excellent mother, taught them their 'cat' skills and was always on guard. She brought them to me at the time she couldn't feed them anymore on their own and knew I was a good source:-). It took about a month before I could get the three kittens indoors - Mollie wasn't a problem - and get them safely ensconced in a box in the kitchen. One of the kittens went to a new home when it was about 4 months old, and Mollie continued to nurse and mother the other kittens until they were about 18 to 20 weeks old and then she became very aggressive towards them and wanted nothing to do with them. She was happy staying inside the house but any time one of the kittens came near here she would hiss and growl. I found a new home for Mollie a few weeks later and kept the two kittens. It all seemed a normal part of weaning - she knew they were alright and she had taught them everything they needed to learn from her and it was time for them to be on their own.
Interestingly, my mare did a similar process with her daughter. The filly was a late born fall foal and so we delayed full weaning until 7 months old. By that time Kassan was quite happy to spend time with the herd and away from her daughter. The night we separated them for the first time overnight, Kassan just put her head into her daughter's stall, looked around, then happily walked back into her own stall and that was that!
Nature has a way of taking care of these things, it seems.