1) Change the password. Use something secure. long and with numbers and letters. Make it difficult to guess.
2) Make sure your AntiVirus is up todate and do a full scan.
3) Download, install , update and scan with
Adaware click here
Spybot click here
Spyware Blaster - click here
If running XP MS Anti Spyware click here
5) Do an additonal online scan at click here, click here and click here
to make sure you have covered all bases.
5) Would a complaint/query to her e-mail provider or the police be of any use?
Yes. See if they can establish whats going on.