The Special Power of Women

This week's Torah portion of Tazria tells us that when a boy is born, the schedule is as follows: The mother is in a state of Niddah – ritual impurity – for seven days; on the eighth day, the baby is circumcised, and the mother begins a period of 33 days in which she is pure despite any discharge (although she may not touch something holy or enter the sanctuary). If a girl is born, the mother is impure for 14 days and pure for 66. The question begs itself: Why is everything doubled when a girl is born?