Have her change her MySpace password. That's all she has to do.
There's a post on Tom's myspace about this. The method being used to get her information is called "phishing." It's spread mainly through bulletins. Users will open a bulletin which takes them to a page that looks exactly like the MySpace login page, but if you look at the url, it isn't.
Try to avoid opening bulletin posts that have peculiar names, and always look at the url when a login screen appears to be sure it is the official MySpace login (
http://login.myspace...)