This... this is BEAUTIFUL! First, I really love the way you drew those tantalizing green eyes >w< From there, I also love the way you drew her luscious, cerulean blue hair, and the way it drapes like that. And lastly, excellent work on that soft, beautiful smile :3
If I commented on all of the pics, the praise would probably start to sound same-y, so I'll pick my favorite one, the Chrysalis one, and lay down a blanket statement that these are all amazing.
The two sisters, ever-regal in their expressions, the somewhat sneering Trixie, Pinkie's exuberance, (plus I like what you did with her mane hair, and of course Chrysalis is just plain awesome. (Though I may be a bit biased there...)