Mistletoe Mistress by Nicola Davidson

Banished to the country for wayward behavior, house maid Miss Rachel Lindsay is near-penniless and desperate. A cruel trick left her abandoned at an isolated country inn on a snowy Christmas Eve, and her only hope is a wealthy, stern, and sinfully handsome stranger—masquerading as her husband.

The new and reluctant Marquess of Kyle, Arran Elliott's journey to London has been halted by a broken carriage. His bid for lodgings is failing—until a mysterious beauty boldly announces they are wed to secure the last remaining room. But when their friendly bargain turns into nights of scorching hot passion and sensual discipline, Arran knows he can't let the spirited and deliciously curvy Rachel go. His—and her—secrets be damned...