Starting with Victoria , there has been over a 120 years of a reigning Queen compared to around 50 years of a King. The reigns of Charles and William would probably mirror Edward VII and George V length so that maybe 40 more years
Still more time for queens than a king. I think that the fact that if a girl she would reign has boosted the girl hopes. I think a boy would have an easier time with the interest not having to worry about fashion, hair and weight issues like a girl would.
It really doesn't matter what baby c is as long as he/she and Kate are well after baby c comes.
I am hoping for the Middleton hair gene to trump the balding gene from William. Grandpa Mike has some nice locks.