in fact if down's syndromes reproduce not only are all of their children male, but they possess incredible mathematical abilities and also they are able to sustain erections for up to half an hour, and I hear the semen tastes incredible (this part is just a rumour though the rest is true it was on mythbusters)
With haemophilia (when the male parent is affected and the mother is a carrier) you have a higher possibility of having a male child.
1 out of 2 girls would miscarriage (the other one would be a carrier) - so you can get only 1 girl
Both boys are able to live, but one of them is affected by haemophilia.
So you have 1 possible girl, whereas having 2 possible boys.