First, the pros. The coloring is fantastic. The grass looks soft and Applejack fits right in there. The outlines are very smooth and appealing to the eye. Her mane and tail flow and looks just as soft as the grass.
Though, there are some cons. Her back hoof looks a bit twisted and it looks somewhat uncomfortable. The fluff is cute, but a little unnatural on a pony. Her right eye looks odd and kind of disrupts the calm feeling that the rest put off.
Last thing, her ears look a bit big. Not too big, but slightly off.
Overall this is a great piece and I hope you continue to do such lovely work.