What if I have five or six toddlers left but all my adults have died? Shall I just send the babies off in a raft and start over or do the babies have a chance of growing up?

It depends entirely upon how much food you have available to sustain them until they're 14 years old and can begin gathering food for themselves. At normal game speed, a 2-year-old will turn 14 in about 24 hours. If all of your toddlers are 2 (which would be the worst-case scenario), you'd need at least 1000 food in the bin to keep them from starving to death. If you have significantly more than that, they probably won't even lose health before they turn 14. If you have less than 1000, it will be dicey.

YAY! They made it through the night and all but one are 14-16. Now they can get to work and accumulate food and research for points. I don't know how I'm going to train a builder though.

If you haven't completed all of the first 9 puzzles, there should be plenty of opportunities to train builders. If you'd like, you could send me a private message with where you are in the game, and I could let you know what the prospects are for your little people.

The Sims in this game Age really fast or is it because of a reason?

They age depending on which speed you're playing at. If you are playing on Fast, they will age much quicker than if you're on slow!

Here is a great post from Barbara that explains it quite well...
"Game speed settings affect how quickly your villagers age, how quickly they produce things like food, construction projects, and research points, and how frequently Island Events occur. The advantage of slowing the speed down is that you don't have to check on your villagers as frequently to make adjustments in the game. The advantage of the faster speeds is that you don't have to wait as long for things to happen in the game - but you also have to check on them fairly frequently. The speed setting does not affect the movements of the villagers while the game is running - they don't mosey around the village on slow speed, nor do they run around the village on fast speed. "