Exchange Student

So an exchange student currently lives with me and apparently she's been using my computer in an attempt to fucking trash my rep on various sites. I had a suspicion she was up to some shady shit but never could prove anything until a few minutes ago when I caught on my computer, should've honestly just made another password instead of being lazy and ignoring my password reset on my computer. As of this moment I have 2 emails that are filled with spam and I can no longer use a Skype with a name I've grown quite fond of. This honestly sucks balls, going to try to get her kicked out of my house so she can't return next year.