i've just been landed in the same boat, my wife is a board member of a local pre prep school, and as my son goes there and has started to fly rockets with me and talk to evetyone at school about it, the school now wants me to go in and do "something"
problem is the age range in 2 - 4 year olds - which if my 4 year old is anthing to go by, are not great at building stuff.
i'll probably go with (have to buy before)some stomp rockets and launch a few low power rockets for them to see.
i've gone building rockets with older kids
make sure you constantly talk about safety, especially with the model knifes.
and use glue that has a grap factor and sets faster than standard white glue, the last bunch of kids i used white scholl glue with, just did not have the ability to hold a fin on whilst white glue set.
most importantly...
well done for doing the build session - you will be your daughters hero (you probably already are)
UKRA 1547
L2
Midland Rocketry Secretary