While I was working in london my ex-fiancee (who was living in South Carolina at the time), entered by Yahoo email account and deleted all emails relating to herself. She did this by stealing my laptop (which was in SC), within which all my passwords were stored. She then proceeded to move in with another guy.

I assume that her IP address entering into my email account will be logged (and different to the IP address that I use in london). Moreover, I assume that Yahoo would be able to restore deleted emails.

Assuming such evidence could be provided, is there any civil or criminal action that could be commenced against her. She also stole numerous items from my home in sc (tv, dvd etc) but that is incidental to this question. I have of course changed all my passwords since.

i assume that yahoo would be able to restore deleted emails.
That's a bad assumption, Yahoo would not offer at all to un-delete these. Webmail comes with a EULA as well, best to read it all (at the risk of falling asleep where you stand). I am not a lawyer but you'd have a very difficult time proving that you were not 'at the controls' as it were.

You are up the creek without a paddle.
Sorry about that but you are operating under false assumptions here.

You can try begging your case to Yahoo, but you have more chance of being named the next POPE.