Nicole,
OK, a few ideas off the top of my head based on the weight of the subject matter:
"Spare the Rod" (and spoil the child!)
"Small Wisdoms"
"Patience" (an essential quality to have when dealing with children)
"Children of the Light" (a bit of an obvious photographic connection but also perhaps to the light they may shine etc.)
"Now Hear This" (a reference to giving children a voice)
"Seen and Heard" (as above and a contradiction of the children should be seen and not heard maxim)
"The Least of These" (a biblical reference referring to what Jesus said about the importance of children)
"Past and Futures" (incorporates the older community)

Good luck with this. Not an easy job, trying to distill an exhibition into a few pithy words which captures your feeling and vision. I'm sure you'll come up with your own fine title eventually!