I can totally understand her wanting to know in advance so she can prepare for the baby with the nursery and everything. I do know couples where only one of them have found out though and the other knows that they know and it seems to work fine for them, but if she is wanting to know so she can start painting, then that ain't going to work for you two is it LOL.

I only time I ever found out what I was having at the u/s was with this pg - all the other my DH wanted to wait and get the surprise - which was great to get the 'it's a boy' etc. So I know but my Dh doesn't know that I know. Sometimes the decision is taken out of your hands entirely though if the baby isn't in a good position to see though.

Could you come to a compromise with her in that she wont go and buy blue/pink paint etc, but can still know. She can still make all her plans for that without actually doing anything.