looks like focal length and shutter speed were fine together, combined with IS, you should be in good shape with respect to motion blur. At the posted resolution, it looks great. Does it fall apart if it's a little bigger?
Yes when the resolution is expanded its becomes blurry. I see lots of pictures on here where the eyes are tack sharp. When I zoom a little on light room mine are no where close. I am trying to get images like that when I shoot.