H1N1 at work

I work in Wilmington, Delaware. I had a mild case of H1N1 and was out of work for a few days. I returned to work on Friday, 10/23/09, and left within the hour because a co-worker called my boss to complain. I returned on Monday and she again complained to my boss, so I left after 3 hours. She said she was going to sue me and my boss if she got sick. My boss requested I get a note from my doctor and have it faxed to the co-worker. I did that today. The note was from my doctor's perscription pad and stated that I was able to return to work on Friday and was not contagious. The co-worker called my doctor's office, asked a lot of questions about my health, and said she would sue them, too, if she got sick. Is it possible for her to sue for getting the flu? Can I sue her for harassment?
Thank you for any help!

She cannot sue--H1N1 is treated the same as any flu.