As an ex-mathematician, I can say there's a lot more to having a successful mathematics career than simply how your brain is wired. It is far more of a lifestyle choice than simply a job. If you want to solve the hardest problems your best hope is to have long stretches of peace and quiet where you can do nothing but devote yourself to the problem. Also there is the long hours culture, the regular conferences without available childcare, the amount of collaborative work done in the pub, the way everything has moved on completely if you have a few years out, having to move anywhere in the world to get the next job... None of that fits with family responsibilities. Some still manage to raise a family and make it as a mathematician but those are the exceptional ones who've made it through despite the handicap. Most women either don't go into it in the first place or else quit after their PhD's to settle down.