You know that she would of instantly have let you known if she didn't like, want or had any problems with it!! God how I wish I had a sister!!
It would have been better if you had left off the "....I was so drunk" part of your text!! Don't think for a second that if this was the first time anything sexual like this has happened between you two that it's probably about the only thing that she's been able to think about today!! No doubt that she's replying the whole scenario (including your text) over and over and over (hence if you did want it to go further, having left out the just drunk part, she would already know that you want to) !! She's deciding what (liked it, wants more, what if's both good & bad, what if any consequences are involved, just something that happened and leave it at that) if anything, that she's going to do about it.
I agree with the other poster, don't bring it up first and act normal like it never happened. If she doesn't bring it up, than maybe the next time you two go out and get a bit sauced, you can make some subtle comments?!? Play it by ear & best of luck to you :)