What age do you actually enroll your toddler to a prep school? My child is approaching 3yo on Sept. some says I should already enroll her. But I think it's too early.

There are some preschools that accept applicants as young as two years old. If you want to get your kid socialized and ready for prep or kindergarten, play schools are a good option. You might find this article helpful: https://ph.theasianparent.com/metro-manila-preschool-guide-sy-2015-2016/