Steps to invite a child account to a Gift Exchange.
If you are inviting a family and you know the parents have child accounts created, keep in mind that linked accounts are not automatically invited when the parent account is invited. The easiest way would be to first add the child accounts to your Friends list and then you can invite them by clicking the Invite Elfster Friends link.
Another option is to check the Participants Invitations box under the Gift Exchange settings menu.
This allows all the people you invite to invite others and is especially helpful for Gift Exchanges with extended families. Invite the parent(s) and let them know that they need to add their family members to the Gift Exchange.