How do I know she's done work as an escort? I saw an advert last year on the web. She was touring London and was just giving her rates, what she does/doesn't do etc. It listed that she did anal.
Also, I doubt that girls who escort but don't do hardcore can't pass the "battery of STD tests". STDs are rife in the industry anyway. Most regulars in the porn world have genital herpes, HPV etc. They aren't actually tested for these infections. And the STDs that the industry does test for - syphilis, chlamydia, gonorrhea are all easily curable anyway.