Walker's Rules by Joannie Kay

Jessie is determined to find her little brother, but fate has other plans when she's caught in a stagecoach robbery. Forced to disguise herself as a boy to avoid detection, Jessie's troubles only deepen when she's sent to Walker's ranch-a place meant for wayward boys. But Walker's life takes a drastic turn when he discovers that Jessie isn't a boy at all, but a spirited young woman. To protect her honor, the judge decrees a new sentence: marriage.
Now, Jessie is bound to a man she'd rather shoot than share a home with. Walker agreed to marry her to save her reputation, but he may have signed up for more than he bargained for. Can this unlikely pair find common ground, or will their forced union end in heartbreak?