Technically, if you read the EULA...

Either you own the account, which is in your name, and you're the only person who uses it.

- or -

You own the account, which is in your name, but your minor child uses it exclusively.
Which means you never use it, because they do.



I'm not sure if they'd be able to distinguish between your use and your childs use of the same account.
But it is against the terms of use, which we all agree to abide by.
If a GM caught you, at their discretion it is bannable.