I would have to say with confidence that yes, she likes you =] I say this one) because eye contact and smiling simultaneously means she's taking the time to acknowledge you for who you are, not just because you're another random person who walked past. And two) that's what I do to let a guy know I like them: I make eye contact and smile =]
If it's that kind of coy, cute smile then I say she likes you. I smile at most people if I happen to catch their eye, but the guy I like, I try to catch his eye and then I'll maintain eye contact and give a softer sweeter smile rather than the one for everyone else. Judge the situation by the type of smile it is.