I respect your personal experience but we cannot draw conclusions that can hurt a lot of people without backing evidence. I hear stories about how alcoholic mothers get custody of children over responsible dads. We do not have full support from the people in terms of same-sex marriage. In a situation like this, generalization like this probably does more damage than it is worth.

I wouldn't say the mother is happy. I'd imagine she'd be overworked unless she had some help (grandparents perhaps?). However, I'd not make any statement that might be seen as her not being capable of doing as good a job.