Dena makes some great points. For right now?
There are times when distraction is a good choice.
Not something that will send you circling back into the repetitive negatives.
I often over think things or am very self critical. The challenge is to get out of that mode. Instead of letting the negative of "I'm not a girl" take over, think what the girl is interested in. What is your/her favorite music, books, games, poetry, movie, ice cream? What does she think of the thought "I'm not a girl". How could she refute that(but not if that ramps up and argument within).
Try, whatever your situation, to just say okay I'm a girl. Don't listen to any other internal or external argument. What does that mean. If you embrace the idea, her and yourself, do you feel or act differently? Even if you can't take hormones yet, does accepting that idea release anything?
I don't have proof of this. However, I am pretty sure that most folks here have that negative voice inside that delivers a line like that to them from time to time. I know I do. Yet, like you, I am confidant that I am a woman. See, even as I typed that, there was some part of my being that argued with me. I am not listening to that right now. I am more interested in hoping you can find something else to think about. Even if it's My Little Pony.
2-4 years is a long time to wait for something that feels like necessity. However, hang in there. Breathe, relax and reach out as you need to. Try to see a therapist when you can. Who knows, maybe you won't have to wait so long. Know you are not alone. Is there a safe friend or relative you could talk to about this, face to face? Sometimes proximity and touch (a hug) can make a world of difference. The family you have found here is often around to talk. Many of us have been through multiple versions of what you are experiencing. I am not aware that any of us are medical professions so we can't give absolute answers; just what we have experienced, what worked or didn't for us and occasionally what research we have done.
I am on the east coast USA and need to get up in the morning. I will need to go to sleep soon. I don't know if that helped at all. I wish you luck and love and a great life.
With loving thoughts,
Joanna