No unfortunately not. Discounts cannot be added to contactless payment cards.
If you use your contactless card on TfL and you are eligible for a child’s fare you'll find that your account gets debited with an adult's fare, although you are able to use your Debit card to top up your Oyster card.
Currently we'd suggest that if you're eligible for discounted travel, you should carry on using your existing Oyster card or Oyster photocard, but please use your contactless card for other everyday small value purchases.
For full details of discounted fares please visit the www.tfl.gov.uk