Home Before Dark

This book kept me on my toes, and not just because of the arbitrary grammar mistakes. The flow of the story was well thought out and I read through a lot of it with increasing heart palpitations. I love ghost stories and hauntings, especially when in book form. I don't have to worry about jump scares. I do have some questions though...

Spoiler time: So did I miss something or did they not explain who the little girl she was seeing was? Because Mr. Shadow was Elsa and Miss Pennyface was Marta, so who tf was the little girl? Was it a real ghost after all or an imagining? I feel bothered by the relationship between Ewan and Petra. It was inappropriate and creepy. Did anyone else guess that it was Marta as soon as Maggie met her?