Marie is the daughter of Grins A Lot. She's 12 years old, and has a natural affinity for teaching dogs. She'd make an ideal apprentice for Teacher, except Hangdog women are expected to take care of house and children. The Daughter of Hecate would prevent this as well.
Get Marie apprenticed to Teacher - Marie offers the Prisoner a reward to find her dog, Kit, who has gone and hasn't returned. Also, the player can convince the town that it's in their best interest for Marie to apprentice to Teacher (the men could stay warriors, Marie will train the dogs well, Teacher is not long for this world, etc.), then all would be well. Grins-A lot won't mind, especially if the Daughter doesn't.
Marie has not appeared nor is she mentioned in any published game. She was to appear only in Van Buren, the canceled Fallout 3 by Black Isle Studios. It is not certain if she will appear in any future Fallout game.