You know, I just ran into this same thing.

I'm not going to use my buddy's account (he quit playing).
I had to reroll one of my shaman, but, he's only lvl 10 atm so not a big deal.
I just went and bought a battlechest and rerolled him.

I had another account that I stupidly set the first name to Sorrow and last name Harvester. I must have been drunk, don't know why I did that.
However, customer support is sending me a way to change this name sense it is non-sensical and I've been the only one to pay on the account. Lucked out on that one.

My 3 others are good to go. Just bought them all BC upgrades.

EDIT: Your wife's account should be fine since you live in the same house. If a GM bugs you, just say it's your wife playing her account. No way they could prove she isn't...

You surely want to remember that secret question though. Best thing to do is go to the account management page and when it asks for your Login/Pass, click on the "Forgot Password" link. It'll ask you the secret question and such and you can see if you remember it. It'll send you a new password, but, then you can just reset it to the old one once you log in again.