Dr Herbie said:
It's 50%.

The sex of the second child is not affected at all by the sex of the first child; knowing that one of the children is a girl is irrelevant in detemining the sex of the other.

Trust me, I'm a Doctor (of biology) Big Smile

Herbie
The sex of the second child is not affected at all by the sex of the first child;

Ah, but a woman's body isn't a coin flip  Smiley

I have read about the result of a study that shows likely hood of homosexuality in 2nd born boy is much higher than 1st born boy. And it doesn't matter that the 2nd born boy is #2, #3, or not...

The hypothesis is that, as a species, we don't want too many alpha males. I don't know the mechanism in humans that flips XX & XY... but to expand (w/out personal merit) the study, can we say that if the couple already has a boy, then the chance of the next child being a girl is > 50%?