Hi Jen,
As long as you are with them, they will be able to use the FL resident 3-Day passes. Children under 18 are not required to show ID when using special passes.
Here's some info on the blackout dates for the 3 and 4 Day Florida Resident passes (taken from the
website): ** The following blockout dates for the Florida Resident 3-Day Ticket and 4-Day Ticket apply: March 28 — April 10, 2015; June 6 — August 13, 2015, December 17, 2015 — December 31, 2015, January 1, 2016, March 19, 2016 — April 1, 2016, June 6, 2016 — August 11, 2016.
Hope this is the information you were requesting, and please write back if I can be of further assistance!
Best Wishes,
Amanda F.