Hattie Stubbs

Hattie, Lady Stubbs was the wealthy young wife of Sir George. She was also a cousin of Etienne de Sousa.

The woman at Nasse House, whom Hercule Poirot meets, turns out not to be Hattie but Sir George's Italian wife, posing as Hattie. All this to cover up Sir George's bigamy. The real Hattie Stubbs had already been murdered and was buried under the folly in the garden.