Looks like it was just reflex-reacting to her running vs actually trying to get her. As soon as she stopped and turned, it stopped. Had she stomped her foot at first instead or ran at it, probably would have been the other way around. Not what you want to see with your kid out in the yard in any case.
Little kid took the experience pretty well though. lol
Oh, I think the Coyote just wanted to play! And I see Coyotes in the Southern Chicago Suburbs in broad daylight quite often. They like to sit on small hills overlooking a grassy area.