Ehm.. How about a conversation, where you start sheepishly that you have to admit to two things...
Like..
-'I really have to tell you some things...'
-'See, I really like you a lot, but..'
-'Well; see... I hope you don't mind, but.. I'm trans...'
Or something along those lines. That way, you basically leave her out of the equation, while leaving it up to her to make a decision. You're even keeping hér being trans completely out of it. In such a scenario, the clue is that you admit to something, rather than compare to something. The word 'but' is a lot better than 'also,' or 'like you.'

(That'd be freaky. 'Yeah; I wanna hook up, because I'm also trans, and I like you a lot!' Not a good pick-up.)
Another good thing is to really try to make your text as sheepish as possible. Shuffling feet, blushing, looking down and everything. That way, she knows it has absolutely nothing the do with her, and is your problem you admit to, and are not reflecting on her. The not reflecting bit is what matters, I'd say.
But..
Does she like you back? If you don't know, then you've got two things you're admitting to. Might as well do both in one go.