I've said it before, but I wish I'd found MDH when I was a kid, because I'd have been ALL OVER these ghost stories. 
 WTHC is pretty standard--family moves to a new place; malevolent spirit haunts nearby areas and is attached to one person; spirit creates chaos; resolution. But it brings in some other dynamics, too--a newly-blended family still establishing norms; children unhappy for different, but all valid, reasons. It all adds depth and dimension to the characters' actions. 
 (I am still annoyed with both parents and the brother, assuming that the older girl will look after the little sister all the time. Get it together, guys. The brother has youth to blame, but the dad in particular could have pulled his head out of his rump and actually parented his daughter, instead of yelling at everyone for being meeeeeeean to his special snowflake.)