I need a Hero!

I started world building for a Space Fantasy story/ series starter, the Kingdom of the Seven Moons.

I love my main character, Mercia, a simple seamstress in the bowels of the Palace. I love the world, which is a bit retro-robot, lol. They have some tech from Those Who Came Before, which is so far beyond their capabilities it might be magic

This ancient tech --or magic-- changes Mercia's life. 

Mercia is dragged before the King early one morning. He is furious with the head seamstress for an unfinished garment, but she was not available so they grabbed Mercia. He points his Sceptre, which holds an ancient orb weapon, to turn her to dust in his fury.

Mercia reaches to push the orb away in panicked self-defense, and it leaps into her hand, turning the king and all his guards to dust.

She's the new Queen.

But I don't have a hero yet. The scholarly schoolmaster? The Court Jester? The horned monster who doesn't turn to dust but turns into a scarred man? So far each of them has turned out to be far too knowledgeable about how Mercia should proceed and they try to take over all the action.

Hmpf. I want Mercia to move the story. Maybe I need an anti-hero?