Some people identify as transgender. This typically refers to feeling like your body and your gender identity don't totally match. (People who feel that their bodies and their gender identities do match are called cisgender or cissexual). Some people who are born with male bodies feel female and some people born with female bodies feel male.
There are many variations within the transgender community and many different terms are used to describe the range of experience.
Here a transgender teen who identifies as female to male (FTM) explains some difficulties he is having with dating.
"I am a FTM and have been on T for almost 5 months now I really like this girl and from what everyone says she has been flirting with me but from my understanding after talking with her she is struggling seeing me as a man. She has said straight out that she has noticed that my voice changed and noticed facial hair and she is straight, I guess I am wondering if anyone has advice on how to get her to see me as man and to realize I don't consider myself as being gay, the reason I say that is I asked her a question about if she thought I should tell someone I like them if not sure if they see you as a man or not and she replied if she is straight let her be I am not sure if she is struggling with the concept and would like advice before I say anything about liking her a lot and risk losing a really good friend."
Basically, any time you cross from friendship to dating you are taking a risk that the friendship might be affected. But obviously your situation has additional issues.
There is no guaranteed way to make your crush see you differently than she does. But you might want to talk to her directly about the situation. Doing so might be uncomfortable or awkward, but it can also give you the chance to clear up any misconceptions she has and to answer any of her questions.
Really, some people are totally able to accept a trans partner as their gender identity, regardless of their birth sex or what their body looks like. For other people this will be harder.
We have a whole section on this site about straight women who have FTM partners. You should can read about their feelings here. Many have no problem seeing their FTM partners as male.
For example, a teen named Katy writes,
"I am currently dating a transguy. I consider myself straight. Things started with this guy as friends but I developed feelings, and so did he. Occasionally, I 'remember' he is trans, but to the outside world we are any normal couple, and most of the time it is like that. I don't consider myself gay for being in love with him. Because thats just it: HE is a boy. The only time when the fact he is trans actually crosses my mind is when we are in the bedroom, and to be honest you shouldn't rush into that until you both feel comfortable anyway. I am in love with this guy and nothing was, or is ever going to change that. Biologically male or not, he is my BOYFRIEND."
Dating is hard for many teens. But it can be particularly complicated for transgender teens who already face many hurdles in day to day life. Finding a supportive community and understanding partners can seem really tough, but many transgender people have both and I am sure that whether it is with this particular girl, or someone else, so too will you!