I'm just brainstorming from ignorance here,but could she open a Tolkienmail account using your email address and use the new Tolkienmail address to register her nickname here?
But is Tolkienmail working?
I suggest that your friend get an free e-mail account with hotmail, yahoomail, or one of the many others out there. Then come back and register.
From what I understand, the way the PT registration is set up only 1 email account per person can used be registered. Mellie ran into this problem when she registered Frogboy. She had to get him an different e-mail address than hers before he could register for a PT membership.