Sometimes the changes that come with hormones (emotional; shifts in body dysphoria) are good topics for therapy, as can be dealing with other family members, stuff like that. And if you are planning on lower surgery in the future, when you do stop working with her now, leave the door open, so to speak, so you can come back to fill out any required time for another therapist letter.
However, there are plenty of opportunities for your therapist to educate herself on trans issues: books, conferences, online webinars, and that whole "internet" thing. 🙂