CreativeButLazy
marshmallowcreampie
The only way I can see that as possible is if Korra died giving birth, and the child was a bender of the element that was next in line. Remember, Aang was born the very moment Roku died.
No he wasn't. Just because we saw a clip after his birth right after we saw Roku die doesn't mean it happened that instant.
I believe Bryke have said something about a two week or so period that the next avatar is born within after the current one dies. At the very least there would be a day or two.
Hm, really? Since they showed the clip right after, I assumed that the next Avatar was born the moment the previous one died. But then again, if that were the case, it would probably be a bit easier to find the next Avatar, because they'd just have to find kids born on the date the last Avatar died. The first episode of The Legend of Korra implied that the White Lotus members ended up with a lot of false Avatar claims.