Cousin Kate, Paperback/Georgette Heyer

Kate Malvern is rescued from penury by her aunt Minerva. Kate's uncle lives in one wing of the grand household, and handsome, moody cousin Torquil in another. And, when Kate begins to suspect the shocking reason for Minerva's generosity, she has no one to confide in but cousin Philip - who appears to have taken her in instant dislike.