Death of a Gentle Lady — M.C. Beaton

You are cordially invited to the wedding of Hamish Macbeth...

Living in her castle near the village of Lochdubh, the elderly Mrs. Gentle wears lavender-colored clothes and is kind and solicitous of her neighbors. Everyone in town adores her -- except for Constable Hamish Macbeth, who discovers that the old lady's meddling might lead to the closing of his beloved police station. To combat her sly machinations, the unrepentant bachelor proposes to her beautiful maid, Ayesha. He knows that his superiors won't terminate the station of a married man. But murder has a way of making the best laid plans gang aft agley, and when Mrs. Gentle turns up dead, the town is outraged. With suspicion falling on members of the victim's family, Macbeth must quickly uncover the shocking truth ... before more people come to a bloody, not-very-gentle end.