Answer:
Shorter than my four siblings, but easily the strongest, Sometimes I wear a funny hat.
Why shouldn’t you give Elsa a balloon?
A locked sphere without hinges or key. Break me open and golden treasures you'll see
Written on with words of white, Has the color of the night, Is the teacher's best delight, And a student's daily fright
What can point in every direction but can't reach the destination by itself
I fly to any foreign parts assisted by my spreading wings. My body holds an hundred hearts Nay I will tell you stranger things when I am not in haste I ride and then I mend my pace anon.