Merge new registration form with an existing record

We have a PVI and a Pre-School on the same site but have separate registration events some children transfer from the PVI to the Pre-School and so go through the same registration process as new parents and complete a new registration form can there be a way to merge the new registration form information with an existing record on EyManage/EyLog? This would also be beneficial for children that may have left a setting and then return at a later date.