Arella

Arella -- last name uncertain -- is a member of the household of Carson von Mekkhan, Seneschal Emeritus of Mechanicsburg. She's apparently part of the Mekkhan (Heliotrope) family, although her position is uncertain; she might be old Carson's daughter, maybe daughter-in-law (and widow of the deceased father of Vanamonde), possibly granddaughter, or who knows what. We do know that she refers to the old man as "Poppa," for whatever that's worth.

It's Arella who brings Carson the news that a claimant to the Heterodyne throne has appeared in town -- not the pretender Zola, but the real heiress,  Agatha. Needless to say, he's skeptical, but Arella has been strolling around town as usual, listening to the rumors of what happened in Sturmhalten, and she thinks this one may be ... different. She has no idea how right she is.

This bit of news galvanizes old Carson to abandon his comfortable retirement, at least for a little while, and go see what's going on. Once he encounters Agatha and company, all manner of fun starts, so although Arella isn't on stage for very long, she plays an extremely important role in the story. We may see her again.