The Quick and the Dead by Willa Marsh
Clarissa really falls in love with the house - a beautiful Tudor manor in the Welsh marches: marrying Thomas is simply the best way to get it. But life there isn't quite the idyll she expects. Thomas is so busy with the farm that he doesn't see the need for a social life, and his two elderly, eccentric aunts- though charm itself - aren't the most stimulating companions. When Evan appears on the scene, Clarissa is ripe for a little diversion, but the complications that ensue demand Welsh magic to unravel them.