Thanks very much for your help.
As it turns out, I was not the owner -- when I found the link you point out, it offered only "remove" (others in that list offered the transfer option, so I know I was int he right place). I did successfully remove myself, but it hasn't solved my problem.
Apparently the purchase of the upgrades was made while logged into my account, not the actual owner's (even though we used her credit card info). So now, on her dashboard, there is information saying "this upgrade is up for renewal," but it shows that the purchase was made by me and offers no way to renew it via her account.
Is there any way to remedy this? Do we need to let it lapse, and then re-purchase it?