Originally Posted by needtoescape

I think you should be OK with this.

It is not exactly the same situation, but I had no problem redeeming UA miles from my mother's account to my UA FF #. Like your wife, I have a former Delta e-miles account that now has multiple airline redemption options, and when I tried to redeem miles from that account to United, I think I got an error message when I tried to add my United FF #, since my mother's e-miles account was already linked to that United account. Later, I cancelled my mother's e-miles account and was able to redeem from my e-miles account to my United account. So, IME, it seems like the only thing they are checking is that a single FF account is not linked to more than one e-miles account.