Well this sure isn't good!
There's a few things you can do to fix this.
First of all, the most obvious thing, tell her to change her password! And make sure she never gives it out! (And be sure it's not a blatantly obvious password. Like for example if my username was FHuser88 my password shouldn't be things like "FHuser88" or "Feralheart" or anything similar to my username.
If this doesn't work, I suggest asking one of the admins (redlinelies and razmirz can do this, I believe) to check what IP addresses the account has been used under, if it's the same IP address all the time, it's probably someone who's in your house or at your house a lot. This should only be a last resort, though, because the admins and mods have a lot of work to do for the game and really need to be focused, but if everything fails, you gotta rely on something, ya know? XD
If you don't feel like messaging the admins, and or they just don't respond (again keep in mind that they're very busy), have her make a new account. Let the hacker have the account they took and just walk away from it all. Make sure when your friend makes the new account, make sure her password is different than the one she had on her first account!
Now if you want to be a bit sinister (or just do this to tell the hacker to not mess with you anymore), go onto the account that was hacked and delete all the characters. This would probably tell the hacker, if they used common sense, that you were either aware of them or that you changed accounts.
Hope I helped c:
