I took in a pregnant rescue cat 6 months ago. She was a brilliant Mum and adored her kittens. I decided to keep one of the kittens.
Problem is that this past month the mother cat seems to have decided she hates the kitten! It's got to the point where she is constantly growling and hissing at her. Mum now only comes into the house to eat and is then straight back out.
this can be the problem with keeping a mom and kitten because in the wild or a feral colony by now the mom would have sent the kitten packing to go off and fend for herself. have you tried feliway plug ins, and you could go back to basics by keeping them apart for a while and then slowly introducing them back to each other , mom may sought of forget that younger one is hers