hmm lets see if i can put this into terms that won't break the forum rules. /wink
lets say you have your account set up as follows:

Account 1: John Johnson - Dad (you)
Account 2: Jesica Johnson - your wife
Account 3: James Johnson - your son

ok, so now say your setup is like this, according to the Blizzards TOS you can only legally play Acc1 and Acc3 (yours and your sons).
now say Acc2 was your daughters, if this was the case then according to the TOS your can legally play all three accounts. i think you get the picture.
Still wrong. You guys are making this harder then it is. It's actually so simple it's not even possible to make it difficult.

As an adult you can play an account in your name and your name only. As a minor you cannot own an account in your name and may only use an account owned by your parent or guardian.
Eligibility.
You represent that you are an adult in your country of residence. You agree to these Terms of Use on behalf of yourself and, at your discretion, for one (1) minor child for whom you are a parent or guardian and whom you have authorized to use the account you create on the Service.
Real hard to misinterpret. Are you an adult? If no then you are not eligible to create a WoW account. If yes you may create an account and allow a single one of your own minor children to use it.

It's extremely clear that an adult is not allowed to use an account they do not own. The only possible way someone would be allowed to use an account in more then one persons name is if they were a minor child of two parents who each had accounts. I wouldn't suggest it even then unless you want to deal with the ban and sending blizzard proof of everyone involved identities.