Minor has a document: use a valid Proof of Identity (PoI) and Proof of Address (PoA) document (like School ID card) in the child’s name for enrolment (refer: https://uidai.gov.in/images/commdoc/valid_documents_list.pdf).
When should the Aadhaar of children updated
The UID of children will need to update their biometrics of ten fingers, iris and facial photograph, when they turn 5 and 15. Intimation to this effect will be mentioned in the original Aadhaar letter. Alerts will also be sent to the registered mobile number of the parent.