Agree with the fellows above. Just ask her out, and focus on doing your own studying, independently. Either study with her, and just that, at least for a while, or do your own studying, and ask her out, but don't mix both at same time.
You mention lab for your class, so I gather that this is a science class. My advice is to make sure you are kicking ass in that class, for your own benefit, and that will automatically raise your status among chicks, in that environment. I have found this to be true back when I was in college taking science classes, and in my recent comeback to school. Girls in general, are not that good at someo of those science classes, and as soon as they found out I get A's on my tests, they all were making an effort to talk to me, ask me questions, and study with me. Now, you gotta play it right, and know what to do with that. Don't let them just use you, the same way they would use a guy with money, then toss you.