can child account play garden warfare online?

Hi guys,

I recently bought PVZ:GW on the Xbox One. I can play it fine, as can my parents, as we all have adult accounts. However, when my brothers try to play it - both with child accounts, and origins accounts created through my parents' email address - they get an error message saying they need an Xbox Live account to play. They can play other games online just fine, and there are no problems with the multiplayer connection on the Xbox. They both have Origins accounts now, so the previous solution is not working. Can anyone suggest a solution to this problem?