what's the difference here again? biological vs psychological? which is which?

I think there can at most be two sexes in the case of humans. But there can be, in principle, infinite genders!

Could this trait also be inherited from the father of the mother...?
(If you touched on this in your post somewhere forgive me for not catching it...)

That's a good question. I'll have to re-read the study myself but I'm in lack of time now. My recollection was that it was impossible to predict anything as far as women were concerned, whatever that means in relation to your question.

I appreciate your readership and follow!