UNplanned Portrait

For a snapshot it is not bad, it's a bit weird cropping but if that is what you had in frame then that's what you have to work with. Other than that the skin color could use a bit more brightness and a tiny bit of dodging of the shadows around the eyes and corners of the mouth wouldn't hurt either.
But its not a bad picture and with snapshots with no preparation, you have to work with what you got!