The lines look nice, but if you're looking to emulate the MLP style, then her hair is a bit off. Some parts are a little too white, and the highlights are a bit glaring. With Rarity's hair, they use more of a purple tone with a gradient to shade with. Maybe try doing a gradient on the mane/tail colors under the lineart?
The back leg on the opposite side of her body is also a bit long and awkwardly positioned, and the back leg that's closer also looks a little strange. I think it's the lower part of the back leg in the foreground being so sharply bent along with the protruding "heel" part.
Overall, this is a nice emulation of the Hasbro style that could use a little touching up.