Montana Sky: Elof's Mission — Linda K. Hubalek

Elof's Mission is a sweet historical romance set in 1886 in Debra Holland's Montana Sky Series Kindle World. Although this book stands alone, it's story line follows after Nolan's Vow.
Elof Lundahl, a former Fort Ellis soldier and friend of Nolan and Holly Clancy, delivers a grave marker to a Montana cemetery for Holly's father's grave. After this task, he plans to travel to Kansas to start a new life near his friends.
Linnea Meyer, a Swedish mail-order bride, is at the same cemetery burying her husband -- of eight days. Now homeless, Linnea and Jamie, her six-year-old stepson, accept Elof's offer to travel with him to Kansas.
Elof falls in love with the widow and child, but he needs a job and home before he can offer them anything. Then Jamie's grandparents arrive unannounced, changing all three of their lives.

Grooms with Honor Series, and Grooms with Honor Friends Series (available and future titles)

Montana Sky: Nolan's Vow (Nolan and Holly)
Montana Sky: Elof's Mission (Elof and Linnea)
Angus' Trust (Angus and Daisy)
Fergus' Honor (Fergus and Iris)
Gabe's Pledge (Gabe and Iva Mae)
Mack's Care (Mack and Pansy)
Montana Sky: Jasper's Wish (Jasper and Julip)
Cullen's Love (Cullen and Rose)
Seth's Promise (Seth and Lily)
Adolph's Choice (Adolph and Poppy)
Tully's Faith (Tully and Violet)