The way I see it, given enough time, there is always a way around any program or device put in place for protection. Having the applications that were described installed on that PC would help, but nothing is 100% effective. If she was taking every safety precaution to ensure her security, then I guess it could be a corrupt admin (hopefully not likely), misconfigured ISP allowing the 'hacker' access, or possibly a number of other things. I would have her contact her ISP directly and demand help - keep calling until satisfaction is acheived..

BTW, is she going to take any of these measures?