What is the little girls role in Dementium The Ward

I'm guessing that you are her father, and brutally killed her mother.

It mentions twice that a man brutally killed his wife in a newspaper in the first chapter near your door, and on a newscast.

The newscast states that a man brutally murdered his wife (the girl that gives you the iron key in chapter 5 and the dead woman from the flashback in chapter 10 I think) and that they think the daughter of the couple was watching when it happened, and escaped unharmed.

This explains a couple things about what the girl did in the mini-videos.

She saw you, ran away scared, then started crying in chapter 3.
She was behind stacked furniture and pointed at you hatingly in chapter 7 I think.
She saw her dead mom in the flashback, then ran away.

Also, this helps explain some things that happened in the story.

Someone took out a picture of her, her mom and her dad from a photo album, tore it up in three pieces, and the man's face was scratched out.