Cadance : Best babysitter!

I kind of think you have to give some props to Daniel Ingram for this. The musical number did such a great job of really establishing the stakes, motive, and goal of the character, in an effective dramatic, and economical way. Sure, she wasn't really fleshed out to any meaningful degree, personality-wise, but by the time she came in, there really wasn't any time to. Barring significant character development, a strong motivation and clear stakes are still a great way to endear a character to your audience. That alone puts her ahead of most Disney princesses.