The users above have mentioned great options, and they're pretty much the only ones you have. Whisper suggested having your friend check her main email account, which is probably your best go (check the spam folder, too); otherwise, you can wait until the Registration opens up again.
Also, if she can't remember the password to her account, have her make a list of all the passwords she's ever used. Many a time, someone uses the same password for various programs and games, and there might be a chance that she's done the same.
I hope everything works out. If all else fails, you can wait until she can create a new account. Sorry if I wasn't much help.