'Within' is actually more along the lines of 'Fatal Attraction' or 'Play Misty for Me' -- movies which don't fit so neatly into the '[Blank] from Hell' mold because there's some initial culpability for the main characters.

'The Hand that Rocks the Cradle' had a typical, happy family punished because another woman lost her child as an unintended consequence of the family's (well-meaning) actions. The nanny-antagonist sets out to punish them and never wavers; she hates them from the moment she first lays eyes on them. She really is a 'Nanny from Hell.'

I don't think movies like 'Fatal Attraction' or 'Play Misty for Me' would work as well if the antagonist was out to destroy the main character right from the beginning. Those women are deeply troubled, but I don't think you can say they come from hell.

They do end up there, though.