Awesome work. I love how you expressed her personality so succinctly here. There's a certain melancholy to her sitting all alone like that with her head in her hand, but the way her eye wanders and the small smile seems to have a certain playfullness as well. As if saying 'oh well, that's life'. The grey tones really add to this, giving her immediate surroundings a very muted tone, but the vibrant hues out the window show there's so much more out there too.
Long story short, terrific piece and wonderful art.