court systems

The maternal advantage in family court is misunderstood. The vast majority of custody agreements are negotiated between the parents. So while there is a societal pressure to favor mothers, this is mostly a phenomena of parents hewing to that norm and not the government imposing it from above.

It may be true that a divorced mother or a lady felon enjoy some benefit from patriarchal ideals and norms. This is far outweighed by the harm patriarchy does to women (and men).

If you look at the "nurturing mother" norm in our legal system holistically, I think you'll find that it burdens mothers with extra duties and responsibilities while stripping them of rights.