Equating it to role-playing a pony is fking insulting. Why? That's all it is essentially, isn't it? She isn't a boy. Will never be a boy, so she has taken on a typical "boy" way of presenting. That's what role play is. Taking on a role that you are not.
Princess, horse, cat, boy (for a girl) girl (for a boy)
This frustrates me no end right now. My daughter has ASD and hates herself. At 10 she hates her developing body and refuses to look at herself in the mirror. We have had to cover up her mirror in her room so she can't see herself. If someone told her that she could be a boy and stop puberty tomorrow, she would do it if left unchallenged. Because she would do anything not grow up!
What she wouldn't realise is that she has to grow up, and that doing that as her own sex would be much easier for her to manage. She has no idea that she is anything other than female, and to start messing with her head would be damaging.
I have watched a friend's daughter transition and it is NOT anything that I would wish on my child. Emotionally, physically or any other way. She is 16 and already has long term damage because of 3yrs worth of breast binding. Too late for puberty blockers, so they are deciding on next steps. She is also ASD and I do wonder how much of it is down to that. They think they are happier now, but in reality since transition they have struggled more than they ever did. They have left behind all their female friends and are in with a crowd with very dodgy beliefs.
I think society needs to stop lying to kids, telling them they can change sex, and allow them to wear and look however the hell they like without changing and mutilating their bodies. True gender dysphoria is rare.
I understand my opinion isn't going to go down well...