My therapist is genderfluid, offered me a letter straight away.... I told them thank you, I will take you up on that when I am ready. They ask me about how I feel about my transition, how I handle relationships as I come out (contractor owner of construction company) at work, to employees and so forth. What is helping me is just leasing the conversation. The last session I had I asked about resources for children because I know one with an understanding parent. And at the end of the session she led me to a personality test. The test told me about me, and confirmed her "evaluation" of my personality, and gave me more confidence. YOU are the key in your relationship with your therapist, if they are understanding and willing to learn, and you like them and feel safe talking to them, just talk.
They also got me into a trans-friendly primary care physician's office. So, you never know what else can come from a relationship. Just follow your heart when it comes to therapy!!!
Hope this helps!!!!