There are two I've seen so far and there may be others I've not come across yet.

possible spoiler...








i had an adult male adept villager show up in a canoe.

I'm sad that I haven't had many island events so far... just 2 or 3, I think... and they were all weather-related! When's the good stuff start happening? :-)

Possible spoiler:










I had an event that was just like the "Barrel O' Babies" from the last one, and it gave me a boy and a girl. I guess there is always hope!

I've had some events which add villagers to the tribe. Unfortunately, like similar ones in the two previous games, they're unpredictable. I'm afraid that since your third baby is also a girl you're going to have to restart your tribe.