Serious Motion Blur or Seriously Obvious Ghost?

Bought my first Victorian Post Mortem pic on eBay a few months ago. Granted, it is not my favorite type, which would be people propped up in chairs a la Weekend at Bernies, but those are pricey pricey. However, this boring dead guy with a big fan club came with a bonus. Check out the girl on the left, about halfway down the line. The super blurry one.




It's an old picture, but not victorian. Probably 1930's-40's and looks to be Eastern European. Now, naturally we must allow for motion blur in a picture from this era. However, there are other children in the picture, and this girl is the only one moving? If you have a kid you know how unlikely this is. Also, if the blur is caused from her quickly shoving in front of the people beside her, why aren't they looking at her as a natural reaction to someone suddenly moving behind and beside you? It's a ponderable, and I wish I knew more about the subjects in the photo.