I am going to preface this by saying I am likely bias against this genre of comic. As much as I love comics in general, there is little in the "YA" category I enjoy. That doesn't mean there isn't stuff I DO enjoy, there just isn't much. Now on to the critique.
I am already disinterested in the characters because of how ridiculously cliche they are. the nerdy kid makes me think "Martin Sue," since with the name Kevin I'll assume you're male. The touch chick makes me think . . . well . .. about every other nerdy boy, touch chick combo I've seen. Their introductions, him reciting radical facts and mathmatic equations was almost the most boring thing i've ever read. Not because the character interactions weren't interesting (there was some decent dialogue there) but because that kind of reaction has been done a hundred thousand times.
Emily's description of fighting people seems to have served 2 purposes, and one of which is likely unintentional. The first is, it did indeed make her seem "tough" so good job. The second is that she is totally incompetant as a fighter. If this was intended, you did it brilliantly and should be praised for your amazing skills (no sarcasm, honest truth). If this was not intended, then this is simply a matter of research. I, personally, know an absurd amount of martial arts trivia and from your description of the manuever you didn't know the name of, I didn't know it either. This means, unless you can demonstrate it to the artist yourself, he or she is probably not going to have an idea either.
Secondly, anyone who actually tries to kick a knife out of a hand as a primary attempt at a disarm is going to get their foot cut open unless he or she is wearing some pretty heavy boots. And that only works if the knife fighter isn't holding it in a reverse grip (thus meaning he's actually competent at it and not just an idiot with a blade). And that's assuming the guy she's kicking isn't fast enough or trained or experienced to actually catch the foot and stab her in the shin. So like I said, this is either brilliant or flawed, depending on your intentions.
Alright, on to comic formating. Do you have an artist already? If you do, great. If your artist doesn't flake on you, even better! I'm going to assume you've already thought through publication and are formating everything toward that goal, so that is the last I will say on the subject.
My overall feelings with the piece is that there is nothing here to hook me or even make me want to pick up the next volume. The characters aren't all that interesting, the situation is bland with the exception at the end with the funky red-eyed animal but that really wasn't enough. The writing isn't bad, but aside from the voice in his head with a name, everything was cliched and predictable. to be fair though, if you had not added the hints of supernatural whatever at the end there, I would have been dissappointed. But I think that's personal for just me.
