In different ways yet none of them isn't courageous.

Cinderella IS the synonym of courage to me

I'm kinda surprised Rapunzel's getting votes, I mean she stood up to the thugs at the Snuggly Duckling and when she swinging around by her hair at the dam

Most of princesses are courageous in their own way imo, well except for her and Snow.

She doesn't have to do anything in her movie that requires courage.

They each have moments of either doing something scary or overcoming hardship when there were easier paths to take (I do have an idea on who's low on my bravest list but it's a complex thing.)

don’t come at my girl Snow