Can a childs own game be shared upwards to my home xbox account and to their siblings?

This is on my console, just the one console here. We dont have (or want) a house full of them.
Its my home account on it.

If they set the console as their Home then yes, they can share it with anyone else on that console.

Hi there,

on the Xbox One an account can share his digital purchased games and subscriptions via the Home console setting on the primary console, which will allow other accounts on that console to those items (Like Xbox Live Gold).

Please see this link on how to share these things via the Home console setting:

https://support.xbox.com/games/game-setup/my-home-xbox

If this is on the Xbox 360, then I'm afraid each account will require their own Xbox Live Gold subscription

I like to add that a child account that is part of a family will Not automatically have access to subscriptions and games owned by a parent account. These items can only be shared via the Home console setting on the Xbox One console.

Hi Dave,

Thanks for coming to the forums. We understand you are wanting to change adult account to a child account. Unfortunately, this is not possible as the birth date set on Xbox.com is set and is unable to be changed. We recommend

creating a separate child account. You can then set the adult account as
home console then the child account can share any subscription like gold or game pass. Also share any games you own.

Thanks,

Brad

Does the child account have its own subscription or are you trying to share the subscription through the "My Home Xbox" feature?