Some have noted that fathers have begun treating their daughters as if they were sons, as this US Army commercial demonstrates:
However, a more rational approach would be to decide early on to encourage daughters to marry young and start having children, while encouraging sons to forgo having their own children and instead invest emotionally and financially in their nieces and nephews. Even with decades of feminism daughters make poor sons, but the deck is now profoundly stacked in their favor regarding parenthood and custody. The sons and parents could financially support the daughters having children without creating a legal incentive for them to blow up the family and sue for child support. The family would at the same time strongly encourage the daughter to remain married to the father of her children, as this is very much to the children’s benefit. While financial support from a father creates an incentive to divorce and expel the father from the household, financial support from grandparents and uncles could be used as an incentive to keep the family together. In this way a family might have the same number of grandchildren overall but avoid the disadvantages of a system which strongly discourages fatherhood.
I’m not advocating this approach, but I can see where given the system we have built many might decide it is to their advantage to follow it. This is defacto what is already occurring in many families as a response to the unequal legal treatment of fathers and mothers, and we can see this for example in Mentu’s story.