Zenobia

This Witch has strong preferences and never compromises. She is trying to build an acceptable sandcastle, but she can never satisfy herself. She has destroyed and rebuilt her castles so many times she doesn't even remember what she wanted to create in the first place. When she does manage to make a nice castle, she feels much better for a while, but ends up destroying it again. She looks like a young lady, but acts like a little child. If she is interrupted when she is playing with her sand, she cries and goes on a rampage.

An extremely picky witch, who knows nothing of compromise.
She continuously attempts to build a satisfactory sandcastle, but finds fault with every one she builds, knocking them down time and again. By now, even the witch herself has forgotten just what she wanted to build in the first place.
Nonetheless– regardless of the fact that she’ll destroy it in the end anyway– her mood seems to temporarily improve when she builds a fairly impressive castle.
Her appearance may resemble a mature woman, but in contrast, her personality is the very definition of childish. If she’s interrupted while playing in the sand, she’ll start bawling and go on a rampage.