Sorry buddy but it doesn't. Some girls are just naturally happy and smile a lot when they talk. Although of course it could mean she does like you, but it isn't a clear shot way to tell. Only way to tell is for you to man up and make the first move. You can do it the kinda lame way but easy way and say, "how about we trade numbers incase we ever miss class or need help on HW". Or you can just straight up tell her, "something about you makes me curious, I want to figure out what it is, how about I take you to lunch later, whats your number."
Don't repeat my quote, when you talk to her, just say what its natural for you. I was just trying to give you ideas.