A friend of mine has struggled to extricate his son from a potentially abusive situation involving the mother’s second husband. Officially, the courts cannot consider the parents’ genders. In practice, my friend has had to fight a red-state system that still sees the mother as the primary parent despite a joint custody agreement.

But this is a digression. My main point was that we do not know what the father in the letter did or did not do for his first daughter. A lot of comments here are based on assumptions.