What kind of answer would you expect from her? Remember, she's a T, and will give a T-type answer, like turning it back to you with "Why do you ask, button?" You might be able to hint around with a non-T person, but I think she's going to suspect something is up, something that you're not saying. The conversation could get really, really awkward.

If you want to bring it up, I'd be direct but not judgmental. Maybe say something like "I heard something disturbing about you and it's really bothering me. It's personal about you and I feel really awkward, but it's upsetting me because of what happened to me and I don't even know if it's true," or something along those lines. Whatever you're comfortable with. It will probably be uncomfortable for her too but she's in the office and in T mode, and I think her training will make her able to discuss it in terms of YOUR therapy, because after all, it's your session so it should be all about you. Bottom line - I'd go with direct and nonjudgmental and get it over as soon as possible!