The Rancher's Unexpected Bride (Second Chances of the High Country) by Lauralyn Keller

In the rugged Montana Territory, a Boston socialite's bid for freedom collides with a rancher's quest for a family. According to Boston’s elite society, Ella Mountbatten has it all: status, prestige, and a bright future. What they don’t know is that her life as a socialite has become a gilded cage of abuse and oppression under the control of her cruel fiancé and domineering parents. Desperate to escape, Ella flees Boston and seeks refuge in the small town of Harmony Springs, Montana Territory, where her former friend now resides as the sheriff. But with her family determined to drag her back to Boston, Ella's hard-won freedom—and her very life—hang precariously in the balance. Rancher, Cody Brooks, is ill-equipped to be the guardian of three orphaned children. But that’s the situation he’s in after the death of his best friend. Now, what he needs is a wife to help provide love and stability to his makeshift family. So when a runaway heiress arrives in need of protection, it seems a marriage of convenience may be the answer to both their prayers. But with danger closing in from Boston and the challenges of building a new life together, Cody and Ella must confront their deepest fears and desires. Can their marriage of convenience blossom into true love, or will the shadows of Ella's past tear apart the fragile hope they've found in Harmony Springs?