Hm; what's with the grubby little Maricha with the tattered hat? I can only guess she's newly adopted. Doesn't look like a persecuted sibling or slave.
She probably just gets cleaned less since she doesn't participate in the show and doesn't need to look nice, not to mention she might earn pity coins if she's a bit dirty.
It looks like the Marisa isn't really a part of the familly. It almost seems like she saw what was happening and jumped in to take advantage of the situation.