the fact finder (jury or judge depending on what the plaintiff elects).

I would think the Mom has some liability, but her apportionment of liability is highly dependent on what she knew about the dog, its propensity for violence, its reactions (if any) to other humans at the door and otherwise. Mom has a duty to safeguard visitors and invitees to her property.

Daughter probably has more liability since (1) the dog is her property, (2) she likely knew of its tendencies, and (3) it's her freaking dog.

Technically, OP's wife could be apportioned some percentage of liability, but highly unlikely given that she was just standing at the door. The only way I can think that she would be apportioned liability is if she somehow knowingly agitated the dog knowing that her actions would likely result in a violent assault. (Without knowing anything about OP or is wife, I think this is very unlikely to be the case).