Yes. I'm sure there are more but this is one I found.
http://www.flickr.com/photos/ummmur/556640357/
Yes
Her first name is Diana.
All I know is that Roger does have a sister by the name of Diana and I suppose she also lives in Switzerland. I don't actually know where she is now but I presume she was recently cheering him on in...
Diana
Roger Federer met his long-time girlfriend, Mirka Vavrinec, at Syndey 2000 Olympics