Gay Gene Passed On By Females?

This theory on (male) homosexuality makes a lot of sense to me; unfortunately, it doesn't account for females. Basically, it explains how a homosexuality gene could propogate through it's effect on females (the males' mothers and sisters), where it leads them to have more children than average. I remember some studies a while back which claimed that women were much less fixed in sexual preference than men, which when coupled with this theory may form a comprehensive explanation.