It did for us, both times. Particularly this time, because we swayed for a boy, so knowing that didn't work has helped us get over the initial disappointment quickly and get used to the idea of welcoming another daughter.

For us, it makes it seem a lot more 'real', like the little person we are welcoming soon has some parts of an identity of her own. We've almost finished choosing a name, we've spent time getting things ready for her that aren't gender neutral and we talk a lot to DD about how great it's going to be to have a little sister (and to be a big sister). It's been really good for DP as well, because he has a hard time feeling much connecting during pg.