I agree on letting her read the letter. I think it would help her to know how you're really feeling without the intellectualizing.

With my marriage counselor (paternal and erotic transference), I called him sobbing and left a long voicemail after I was upset about feeling rejected when he seemed unwilling to give me a second individual session to discuss the transference. I was embarrassed after I left it, but it let him know what I was really feeling without trying to intellectualize or downplay it--just raw emotion. His response was very helpful--and he thanked me for leaving the message and being open about my feelings.

Good luck!