Being a girl/ connected to womanhood but like being seen as a boy or other. It’s not tomboy cuz it’s not necessarily linked to gender expression.
Thank you 
Maybe one of these?
- Fiamasc
- Boymoder
- Tombro
- Azurgirl
Closest thing I found is boymaskgirl! Very metaphorical, like, a boy-mask slapped onto a girl by others, but I think it still gets the point across!