M.D.
M.,
This is just my two sense, even if they do have a boy they will still ask you for $$$... If you continue to give you will enable them to always depend on you. It's hard but just say NO... Anyway, if they have a boy, are they just gonna ignore the girls they have?
On percentage of having a boy, I don't really know; it's up to the man, he carries the "y". Also, I have a theory, that some women's bodies tend to go for the "x" and not the "y"; but I really have no medical facts and I would still put it on the man's fault for not having boys
Just say NO!