Men prioritise partners over and above other relationships. A mother will only very rarely abandon her children to pursue a new relationship: women are not saints, they have affairs, they break up families, but the children stay with her. This is not the case when the male equivalent if you like happens.
These are simply patterns of behaviour that signify there is a difference between the priority relationship if you like.
There's nothing at all innate in this, it's a function of a still-sexist socialisation which often still sees women's careers as secondary to their function as mothers (this sometimes still internalised by the women themselves as borne out so often on Mn where someone says blithely 'Oh, we decided that me being a SAHM was best for the family') which means that women are both excluded from economic independence and more likely to be their children's primary carers, hence more likely to remain primary carer in the event of the marriage ending. And of course, while not working outside the home, considered to be more 'available' to parents for dropping in, dropping off shopping, collecting from hospital appointments and generally managing family relationships.
Educating girls to fully expect that their work will be central to their lives all their lives, regardless of whether they have children or not, to consider part of their parental role as providing for their children, to consider their working lives to be fully as important as their spouses, and that taking responsibility for their own economic independence is key -- and I think you will see a falling off in assumptions that adult daughters' job is to trot about maintaining relationships with parents, but not adult sons'.