Where should I begin.

When you post something like this you should also post additional information about character, purpose of this animation etc. so people can understand what are you trying to achieve.
First thing that catch my eye are her arms, they are jiggly like they are made out of rubber. Main reason for this is last frame in which elbow almost bends in opposite direction.
Shoulders are to stiff for this amount of arm movement.
She looks chubby, I don't know if this was your intention, but I would remove few pixels from her stomach.
Using of outline is inconsistent. I know that you are trying to create selective outline by changing its color, but unfortunately, at least for me, you didn't succeed (again maybe this is because it's unfinished

). You should maybe try to remove outlines and work with colors only.
Due to shading, if you only look her feet, it looks like she is walking diagonally cause you can see her soles.
I don't know what emotion are you trying to achieve, but if you add gentle head bounce, it will add more happy feel to this animation.
Also her boobs retract by one pixel in last frame, I suppose that you didn't catch this glitch.

When you animate her hair, you should also move shading lines a bit (subpixel animation), cause if you animate just the ends it won't look natural.
I hope that this was helpful.
