I shake a lot in therapy, too, and I dissociate when I am recounting parts of my history. My therapist helps me by helping me recognize what I am feeling in my body, and he provides things for me to do while I am talking about my feelings, like playing with clay or drawing, which seems to help.
I am currently in a trauma sensitive yoga group and a lot of stuff comes up during the talking part of group and the yoga practice, which together is about two hours, which I have been shaking all the way through. The facilitators told me that shaking was a good sign; that my body was "discharging" trauma energy, which actually makes a lot of sense to me. So, yes, I think shaking CAN be a sign of recovery, depending on the circumstances, although I'm not sure what comes next.