You are right — this setting is synced, so it would affect your children’s use of the accounts.
An alternative approach, which is a little more cumbersome, is to log in to the Web Vault, open the Admin Console, and remove your account from the collection access list (permissions). This will hide that collection from your browser extension (and Desktop and mobile apps). If you need to access one of the hidden accounts in the future, you’d have to go back into the Admin Console; there, you can either copy the passwords from the hidden collection directly, or add your account back to the collection access list.