There's a little motion blur, but probably not much you could have done about it. ISO 800 on lower-end cameras, like mine at least, tends to be too noisy so I don't usually consider it an option. The only other way you could have increased your shutter speed was to use a wider aperture (lower f-stop), which wasn't an option with your current lens, or to add some supplemental light with either flash, white cards, or reflector. Aside from that, if you know you're going to be shooting pics of someone in a given orientation, try and use single-point AF so that you can choose what you get sharp focus on... and try to keep that on the eye closest to you, or at least the part of their face that's closest to you if they're moving too fast. Another good guideline to keep in mind is that if a person is looking one way or the other, that the image should continue in the way they're looking. So in your image, the back of her head would be more off to the left side, to where it was almost out of the picture. I like candids, so I usually prefer the shots where people aren't looking at the camera.