You, sir, have frustratingly good line weight, I strive to create good lines myself when I sketch, but yours are flawless. I have a lot of work to do before I get to that level, and honestly, artists like you inspire me to do better.
This, as everyone has pointed out, is also very, very cute.
Wow I just stared quite a while at this. The way you draw ponies is exactly how I would love to be able to do it. The chubby cheeks, big and curvy ears, short but well-defined legs. And her hair, oh my, it looks so 3D!