Happy?
She looks like she is pretty happy or just exhaling her breath as she holds a book going to a class or maybe to her dorm room. I think you could have given a background though. It would have given this drawing more life and details as the viewer would have more of an idea on what kind of a lifestyle she leads and lives by.
The pants and shirt look pretty cute and are very nicely shaded as if the sunlight was hitting her from an angle as well. Her facial expression kind of shows that she just enjoys the day and being with her friends. Also kind of wondering if that is her natural hair color or if she dyed her hair that color awhile ago.
The band in her hair looks pretty cool and makes it look like she doesn't enjoy the wind whipping her hair in her face and there aren't a lot of people who enjoy that unless it is on a day that they don't mind.
Overall, a very nice piece of art.
