Help identifying an old movie
 

When I was a kid I remember seeing this movie, but I have no idea what it was.

If memory serves it was black and white and a family had taken in a woman - possibly to be a nanny for the kids. She might possibly have been a witch, but I remember thinking she was trying to seduce the father.

Anyway, the scene I remember most vividly is when the girls caught a mouse or a mole - some small rodent and wanted to keep it as a pet, keeping it in a mason jar. Later, the woman used a kitchen knife to kill it, mainly because the girls loved it so much.

Does this sound familiar to anybody?