It is interesting, as a parent I have always encouraged mine to do everything, with no gender bias, and dd1 was always into stuff which was traditionally 'boys' stuff. She hasn't worn a skirt since she was about 8. To the extent that I would not have been able to send her to a school without a trouser option. I have never thought anything of it, I pretty much live in jeans and boots for example, but when she said she was gay, I realised that in some ways it was obvious, she has been typical gender non conforming for ever.
As I said it really won't be a surprise to anyone when they find out.
I do think for butch girls and effeminate boys it is very hard to negotiate these lines. Are they just an effeminate straight boy, or are they gay?
One of the reasons I am so worried about some of the trans stuff floating around is that it is these 2 groups who seem to be being pushed towards trans, instead of just letting them work out who they are.
My response to dd has been to continue life as normal, but in the last 6 months the topic has come up many times subtly. And she really appreciates it when I 'get' a gay joke. As an example, she was really routing for Dan on GBBO, because he was gay, and made some funny supportive comments of him which went right over dd2s head, and she and I just exchanged a grin.
In the end, to me, in this age of teenage mental health worries, I just want her to feel safe, loved and free to be herself.