Girls and women know an awful lots about males and females wanting to change sex because:
they have all seen lots of soaps, films, books, magazine articles about it,
they have all been in underwear/dress/shoe shops when guys have tried to buy women's things and its been obvious that its for them,
they have all been in pubs and clubs and bars and seen groups of 'trannies',
they have all got friends whose 'friend/brother/sister/relative' has changed sex or 'gone queer',
they have all had discussions about how they would feel/react/behave if they found their male was seeking a sex change like the one on that days' news,
they all know that in 'that' house there are a couple of men or women and one of them takes the male /female role,
any other things?