It's not that simple. It is well-known from other research studies, particularly the ones which document the effect of social status on gender ratio, that the

It's not that simple. It is well-known from other research studies, particularly the ones which document the effect of social status on gender ratio, that the woman does have an ability to influence the gender ratio of her children. The most likely mechanism by which she does this is altering the porosity of her cervical channels, which could change the ratio of male to female sperm, but as far as I know no one has observed this directly.