It's like getting caught at K-mart by someone you know, no one ever admits they go there (well its bankrupt now but you know what I mean)...What was she doing there amybe she's nervous too?  Does she work in your company and can relate the story to your co-workers?  If you have no common friends or associates then why would she bother telling anyone?  If it bothers you stop her the next time you see her and tell her you would appreciate her not disclosing the info as it could harm you?

Is she a he? CD/TV/TG? look hot? ask her out! LOL! otherwise, leave it be. she's probably as embarassed as you are. when next you cross paths, just act normal. be nice. unless you're not normally nice, then act abnormal. of course you could always look her up to explain how you're doing sociological research for your doctorate on the changing mores of sex in american society which you've been secretly working on for almost a decade and would be really embarassed if anyone found out about how long it's taken you so if she wouldn't mind keeping it under her hat until you publish.....