A Harvest of Hope, Song of Blessing Series by Lauraine Snelling and published by Bethany Books.
Just a few short weeks into her year-long nurse training assignment at the Blessing Hospital, Miriam Antonio is called home to Chicago, where her mother is gravely ill. With siblings to care for, Miriam pleads to be allowed to finish her training in Chicago. Her nursing supervisor grants her a brief reprieve but extracts a promise that Miriam will soon return to Blessing and fulfill her commitment.
While in Chicago, Miriam has tried to get Trygve Knutson and Blessing out of her mind, but his letters make that impossible. Trygve is busy building a house, hoping he can convince Miriam to return to North Dakota and marry him. Torn between Trygve's love and her family's needs, she doesn't know what to do.