It isn't your wife's account - it is your DAUGHTER's account <wink wink>.

You can 'share' accounts with your underage children - but not your spouse. I guess because your kids don't really own anything - you own it/are responsible for it.

let me see if I can dig up the actual verbage-

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.
Anyway - aside from all that - you aren't going to have any trouble.