If your friend did not receive/activate her activation email, it may have worked for a time before terminating the account. In the sense of 'You have a certain amount of time to play without activation and you need to activate your account within that time to continue."
I'm not sure there's a fix, if that is the issue, but the next time registration is open, have her check for that email and activate it, if that seems to be the problem.
If not, she may need to make a new account.
As for the incorrect password problem in-game, make sure she is not using the number pad if she has numbers in her password, as the game will not recognize these keys.
