I usually don't do this because i seriously don't have time for those things, but I like how you asked for real critique which will move you forward instead of "love my art" comments I will not repeat what was already said, here is my opinion showed also on your artwork, if you don't mind. First of all, ANATOMY please, DONT hide limbs under tail/hair if its not necessary or purpose. A LOT of artist do this and is looks (and usually it is) like hiding you lack of knowledge of anatomy. There are plenty tutorials at the internet. Study them, and don't do this next time. It will look better even with some mistakes, than with all hided limbs.
Next is SETTING UP SCENE
Dont... cut...limbs... never..ever. If its not purpose of close-up frame or something. Seriously, try to draw head/torso/ or whole body. Don't set up scene like you did now.
After that is SHADING Not bad... but don't do this mistake : edge = shadow .. thats WRONG Set up light source and imagine that pony in the space. Is that hoof in shadow? should be this ear highlighted? if yes, how much? Just some lame corrections i did (i also corrected that shadow at her belly)
Almost last thing i should mention : HAIR Download brushes if you are using Photoshop. Study photos of women with longer hair. Those hair you did looks little like bouffant. And they don't look soft at all. I hope you don't mind all those tips i gave you. And definitely last thing to say : DONT..STOP...DRAWING.. You are on seriously good way to become awesome artist. You need more practice, but you did great work here. GOOD LUCK AND KEEP UP GOOD WORK!