The Skeleton in the Grass — Robert Barnard

A KILLING PEACE
It was 1936. The clouds of war gathered over Europe. But in the small English village, new governess Sarah Causeley was enchanted with the Hallams of Hallam House: the cucumber sandwiches at teatime, the charming conversation, the passionate concern with peace and principle. That's why the nasty pranks came as such a shock. Someone in the village was waging a hate campaign, making the Hallams victims of cruel taunts that could lead to terror. But until the dirty tricks turned deadly, no one guessed what real malice grew in the countryside. Or the identity of the killer who left on the gracious Hallam lawn both a skeleton...and a corpse.