@Keiran That's what I thought at first too, but I watched it recently and she said her third GREAT-grandchild. (I've been watching them all again)
As for Korra's abilities... I think her complete control over the avatar state is a little ridiculous. I'm glad the spirits are finally showing up, but I'm not sure how much I like their reappearance. What I mean by that is, in the vid in twilightblade's post, the spirit looks less like the ones from A:TLA and more like a monster, making it seem more like a scooby-doo kind of situation or a ghostbusters situation instead of the spirit world I know and love for the first series. However, I won't judge it until I see it. The second season will DEFINITELY be interesting. I'm especially interested in Asami taking over her father's business/Korra and the spirit world. Actually, I'm only not really interested in Mako's storyline haha.