Two stand up comedians, united by a common interest in all things scientific, we know that the difference between the sexes doesn't boil down to shopping and map reading, but to the SrYgene.
There is, however, at least one way that a fetus without an SRYgene can be exposed to testosterone in the womb and that is if she has a twin brother who is releasing his hormones into the fluid that bathes them both.