This mod adds the missing companion, named Nora, to the game.

What is she doing?

She is in the basement of the house, which is occupied by your friend, Shaun. However, your friend is not there, and Nora is looking for him. She is a human being, and so she is searching the house. She is searching for her husband, and if she finds him, she will kill him. However, your presence in the house can help her, because if she sees you, then she will not go after her husband.

Why is she searching for him?

Because she is a mother and she wants to protect her son.