"Sir Guy's Atonement" (Book 3) by Gratiana Lovelace, 2015 (a Wattys2015 Nominee)

If we could go back and change one thing in our lives--a careless thought, a hurtful remark, a devastating action--who would not wish to undo a wrong, or a mistake, or a regret? And yet, the past cannot be undone, wrongs cannot always be righted, and regrets must be lived with. And Sir Guy of Gisborne must somehow find a way to live with his pain and guilt of killing Lady Marian Knighton and harming others--if not for his own sake, then for his growing family’s sake. Sir Guy’s loving family is his greatest blessing. But Sir Guy's happiness will be challenged in a way that he never thought possible, when an old spectre from his past misdeeds returns to haunt him. And Sir Guy will finally have to atone for what he has done.