I worry about similar things with my T. I don't know if she will be able to hear the harder stuff. She too is a trauma T and has worked extensively with trauma. She does EMDR so does a lot of both "simple" and "complex" trauma, but still she has sometimes seemed like she was struggling to cope with some of the things I have shared. I don't want to traumatize her either!
No ideas, sorry, just similar concerns. I think I should probably ask her about it (ummm, how?!)