Design wise, I have no problems! Character wise, no clue! O-o I've yet to get a chance to read through, but I can't see WHY anyone would have a problem with her.
Of course, she's no Dark Lord Shadowhoof the red and black Alicorn husband of Celestia, Luna, Fluttershy, and best friend to Derpy, and the rest of the Main Six, but then, who is? /obvious smartasness.
In all seriousness, she seems fine! Screw people who insult others for no reason.