Definitely tell her. It would be a great opportunity for you to express a personal boundary in what is presumably a safe environment. That could be very healing in its own way.

Touch is very personal, especially if you have had a bad experience in the past. My therapist hugs and holds onto me a lot and it's very healing because she always asks permission, but I would never in a million years let another therapist touch me at all, so I totally understand where you're coming from on this issue.