Yes. You can buy an Epic Season Pass for children aged 5-12.
Age categories are determined by purchase date. To be eligible for a child/senior Pass for the season, the child must be within the age range at time of purchase. Once purchased, the Pass is valid for the entire applicable season and will not be restricted should the Pass Holder no longer fall into the age bracket.
If you are enrolled in Auto Renew, and your child moved into a new age bracket on or before April 6, your child's pass will be moved into the next appropriate age bracket. Age categories will be verified each year against the birth date on file, in order to confirm the specified pass is appropriate for the actual age of the Pass Holder. Guests will automatically get moved into the correct product age category while enrolled in the Auto Renew program.