Kit McBride Gets a Wife — Amy Barry

The four McBride brothers have their worlds turned upside down when their precocious younger sister secretly places an advertisement for a mail-order bride.

Kit McBride knows that Buck's Creek, Montana, is no place to find a wife. Between him and his three brothers -- plus little Junebug -- they manage all right on their own, thank you very much. But unbeknownst to Kit, his sister is sick to death of cleaning, cooking, and mending for her big brothers, so she places an ad in The Matrimonial News to get them hitched.
 
After Maddy Mooney emigrated from Ireland, she found employment with an eccentric but poor widow. When her mistress decides to answer an ad for a mail-order bride, Madd​y is dragged along for the ride to Montana. But en route to the West, Maddy is suddenly abandoned and left to assume the widow's name, position, and matrimonial prospects….
 
With no other recourse in the wilderness, Maddy must convince Kit she's the wife he never knew he needed.