If a parent very blatantly and obviously manipulates one of the children out of the relationship with their father.
But lets the other child get on with it. A possibility: the other child is not so dependent on the mother, getting bonding and emotional stability from the father.
Only to be able to turn around and accuse the father of giving one child more than the other. All the while having done everything to break the child’s relationship with the father by acting as if the parent was the child’s ally, using communication patterns of a teenager, accusing the father of bullying when he tried to parent, and then crushing her child, letting her know her father rejected her, so she can be the saviour, playing pingpong with the child’s mental health.
Is this a very strange form of Münchhausen by proxy?