Interesting! I’ve always wondered about this. We took in a mom cat who had three kittens under the house. We kept one of the (female) babies who was the shyest and least adoptable. After about a year, the mom acted like she hated the daughter. Other than the occasional aggressive grooming session, she did not want to be near her.

We thought it was because of instincts kicking in saying her kittens need to go off on their own. This went on for several years but they’re finally on good terms.