I haven’t ever done it but I guess the key things I would think of are:
1) reviewing/pulling together your learnings, takeaways, progress from the work you have done together (sounds like you have already done this?)
2) looking forward to focus on your next steps - whether that’s supporting you with transitioning to a new therapist or looking at what you need to go it alone. Are there any possible challenges ahead that you can think of that you two might be able to come up with some ideas for together. Including do you need any support from her in how to transition away from your relationship with her?
As for anything else such as if/how you want to go about thanking her in some way or how you want to approach the actual “goodbye” moment, I would say to just go with your gut and do/say/be whatever you feel you need in that moment to feel “complete”. I don’t think there are rights/wrongs or should/should nots about this. Therapy is such a personal process -including the ending of the process.
I know your therapist is going on a sabbatical for a number of months - are you hoping/open to the idea of picking up with her again when she returns? If so, you may want to say/ask something around leaving that door open for the future?
I imagine this is a hard time for you
@UnicornSightings - it definitely would be for me.
When is your final session?