She is not "preteding" to be a girl; she is one, but she does wear femenine clothes, I definitely think this is something she'll stick to in the long run.
I totally understand how you're feeling, cleverquacks. You've just started to view your child in a totally dificult perspective, of course it's going t be hard. Good luck with it all; I wish the best for you and your child.
She's not waiting for any gender clinic appointments, she's had some counselling and as far as surgery goes I don't know if she wants any/what surgery but I'll support her though any/all of it.
I don't think mermaids is too bad flashbac, and yes, she's been diagnosed with gender disphoria by a professional therapist. She's following a bunch of transgender/lgbt+ celebrities on the internet which is giving her support.
Merribloomzoothief, of course she can dress/present herself anyway she wants regardless of gender, but she has a condition called gender disphoria which is basically an allround discomfort about her gender (when she was "a boy"). And, in answer to your next question, I would advise for them to allow as much freedom as possible with regard to how the child dresses/presents.
SD1987, this is a common opinion that transgender girls are more "girly" than cis girls and trans boys more "manly". I suppose this would be true for my daughter (she likes pink, wears dresses, has long hair etc.) but obviously transgender girls can present in anyway they like and still be girls, same as cis girls. As far as schools go, both her school and all of the students have been very supportive of her transition.
PinkFluffySlipper63, I would advise for you to connect to your son on a personal level as much as possible: make sure he knows he can come to you for help. I admire your support of him through this journey. All the best for you and your son.
Italiangreyhound, in the UK, pre-adolescent transgender people can access hormone blockers at a young age, which essentially prolongs puberty. The beauty of these is that if they change their mind, they can go off hormone blockers and have a normal puberty with no harm done. Most GPs I've talked to are unwilling to prescribe "Cross sex hormones" (estrogen, testostorone) to anyone under 16, possibly 18. These will make irreversable changes to their body and psyche, so a greater responsibilty is needed.