Sorry if she's not the best. ^-^ I tried to add in everything you wanted -- alicorn, long wavy mane, dark mane, light body, sword for a cutiemark, jewelry, and some royal stuff. :3 I'll post an image of her without her accessories in a minute.
She's wearing a circlet and the royal shoes. ^-^ As well as a locket. The talent is just a suggestion, feel free to change it if you'd like!
If she doesn't win, I'll probably keep her. :3