Actually, she wasn't "the woman of the house." Here's the story:

On July 13, 1793, a young Royalist from Caen, Charlotte Corday, managed, by a clever subterfuge, to gain entry into his apartment. When Marat agreed to receive her, she stabbed him in his bathtub, where he was accustomed to sit hour after hour treating the disfiguring skin disease from which he suffered.

She was sent to assassinate him.

Don Firth