Wow, best of luck with that Jenny. I'm sure everything will go fine, and it'll probably be quite a thrill to be able to do that.
The thought of me doing it down the line fills me with the utmost dread, and not just because the years I had spent at school are years that I'm delighted to have done with. I guess it depends on your experience of it really, but I left with a number of people who were content in making my life an utter misery (probably didn't help that I just sucked it all down for 5-or-so years, but there you go!). There's one person in my entire school year that I speak to, and that's completely by chance that she started working where I worked. She's also one of about 5 people I know personally who are aware of my intent to transition. I was only recently in a bar in which somebody from school happened to be as well, and even that resulted in derision for no other reason than simply being there - and I was presenting as male at the time!
I'd consider moving far away before seeing most of the people from school ever again. 🙁