Applejack Trotting

This isn't a terrible animation to start off with, I've seen many worse and I can tell you at least tried, but this doesn't mean it can't be improved.

One problem I can already spot is the outlining in several spots;

-The tail
-The hat
-The part of her back slightly covered up by her mane
-Her face, her muzzles, not her eye or anything.

Honestly I don't know if was unseen or unintentional but it's really more of a personal preference to me.

The other issue I notice is you only used probably only two pictures. I only note that as a problem because the movement's choppy and skips. If this was a test, I could excuse this.

Anatomy wise I see no issues and overall everything else appears good. My recommendation is that you add more pictures into the animation. It would make the movement way smoother.