As with all of the VV games, make sure you have your children picking the mushrooms that appear anywhere on the island.
You can get general food tips in
this thread.

Otherwise, you can take a look at
the official VV3 Guide which contains
major spoilers on how to feed your villagers or you can take a look at
this thread. Keep in mind, both of these contain
major spoilers about the game in general so if you don't want anything wrecked for you, I would suggest taking a look at the first thread I gave you.

Hope this helps!
