A French straight to TV movie I saw years ago called “Les Fleures Sous la Neige”. (Flowers beneath the snow.)
A movie about a young girl who is mistreated by her step mother.
There’s plenty of movies like that, but the fact that this one was low budget seemed to demand much work from the actors, so it seemed a lot more “real”.
However that most likely doesn’t fit the context of the question, as it’s scary indeed, but not in the way a horror movie would be so…
If you consider Eraserhead not to be horror, well it freaked me right the hell out. :/