Silence by Meg Hendry reminds me a little of the movie, Boogeyman. I like this story, but it feels rushed in some places, and I think Hendry could turn this into an excellent horror novel if she wanted to. I also think Hendry could have included a detailed flashback of what happened to the other children in the house.
This story reminded me of a family I babysat for during high school. The had a baby, a 3 yr old and a 4 yr old. As disgusting as it might sound, I didn't feel comfortable leaving the kids alone when I had to use the bathroom. Luckily, the bathroom had plenty of open space, so we weren't crowded. Anyway, I sure as hell wouldn't leave a little kid alone in a house that has something dark and sinister lurking in the freaking hallway.