The Duke’s Wicked Widow by Caroline Lee

They call him the Duke of Death, but he’s her last chance at a life worth living!

To Society, Fawkes MacMillan is a nobody; a hanger-on at the edge of respectability with a murky past and an even murkier lineage. But to Lady Danielle Aycock, he is her only hope of salvation before a horrible Christmas deadline.
Having recently lost both her husband and her father, Danielle’s only chance to save herself and her stepdaughter from destitution is to announce her pregnancy with her husband’s heir, therefore prolonging the settlement of the estate. The problem? She’s never been pregnant, and time is running out.