Across a Broken Shore by Amy Trueblood

San Francisco, 1936. On a day when Willa MacCarthy is supposed to be meeting with her parish priest about taking her vows as a nun (something she does not want, but her Irish-Catholic family insists on), her brother Paddy slices off parts of two of his fingers while working at the family pub. Willa, who secretly reads medical books in her free time, knows enough to create a tourniquet and take Paddy to their family doctor. When she gets him there though, she learns the old Doctor has retired and a new Doctor, a woman, has taken over his practice. 

The Doctor, Katherine Winston, stitched Paddy up while Willa watches in awe. Noticing her interest in medicine, Dr. Winston offers Will a job, as she needs a nurse. Willa declines though, knowing her family would pitch a fit. However, Paddy talks her into doing the job, and promises to help her cover it up from her parents. They end up telling Willia's parents that she and Paddy will be helping a few times a week at a soup kitchen. 

On her first day helping Dr. Winston, the Dr. gets a message that she needs to attend to some injured workers at the Golden Gate Bridge's field hospital (as the bridge is under construction and the work is very dangerous). Willa goes with her, and runs into a handsome young man she had seen once before at church, who is an iron worker on the bridge. Willa has a pretty terrible experience stitching up a head wound on Sam's drunk cousin Benny, who fights against having a female Doctor and vomits all over Willa. In order to get home looking somewhat presentable, Willa lets her best friend Cara in on what is going on, since Cara knows about her interest in medicine and even helps Willa by checking out medical books from the library for her. 

During her conversation with Cara, it is revealed that Willa promised to become a nun at age 12 after her mother had a miscarriage. Cara tries to make Willa see that she does not have to follow her family's expectations over a promise made when she was a child, but Willa still feels deep guilt about lying, especially when she hears that a friend of hers who was supposed to join her in the convent is pregnant and has run away with the baby's father.

While continuing to work for the doctor, Willa befriends the Cleery's, a family living in a Hooverville, and begins visiting them out of concern for the pregnant mother and her two children. Benny gets drunk and severely injures himself again, and when Sam can't find Dr. Winston, he finds Willa and asks her to help, as they can't risk bringing Benny off the bridge because of his injuries. Unfortunately, two of Willa's brothers who have been working on the bridge are nearby and discover her secret. They agree to keep quiet about it as long as Willa doesn't tell their parents about their own gambling and partying. 

Soon after, Dr. Winston takes Willa on an excursion to her own medical school and introduces her to some of the faculty there, hoping to inspire Willa to attend. Willa is fascinated but also distressed as on the way to the school, she runs into Cara and her mother, and is afraid it will get back to her parents that she was going round town with a woman they don't know instead of working at the soup kitchen. A few days later when Cara's parents throw a party, Willa is afraid this is when everything will come to light. Instead she runs into Sam who gives her the gift of her own stethoscope, but has to leave the party when several people discover he is a Protestant. Willa also learns at this party that Cara is planning to move to New York just a couple of days after Christmas to audition for Broadway shows. 

A couple of days after the party, Willa runs into Benny on the street. He asks to have coffee and tells her that she should not believe anything Sam has told her about himself - that he tells the same tales to girls in every city they go to and that he does not plan to stay in San Francisco. Willa is devastated and confronts Sam who tells her Benny is lying in an effort to keep them apart because he is afraid Sam will actually want to stay in San Francisco, where Benny has already made a bad reputation for himself. Sam tells Willa Benny's alcoholism is really why they always move, and the two reconnect by going sight seeing together. 

Unfortunately around this time, the Hooverville where the Cleery's are living is raided once more. Mrs. Cleery is arrested for hitting an officer with a frying pan and the two children are taken to an orphanage. On Christmas Day Mrs. Cleery goes into labor and Willa helps deliver her little boy. An uneventful month goes by during which Willa and Sam manage to visit the Cleery children in the orphanage a few times. 

In late January though things get incredibly messy when Dr. Winston takes Willa with her to the home of Molly, Willa's former friend who previously ran away with her boyfriend. Molly is near death after having given herself a home abortion with a knitting needle. Molly's parents recognize Willa and beg her not to tell anyone about the incident. This gives her flashbacks to her mother's miscarriage, which happened because Willa, in a fit of childhood anger, pushed her down the stairs. The entire event proves too much for Willa, and she tells Dr. Winston she doesn't want to help her anymore. She also breaks off her relationship with Sam and tells him she WILL go into the convent in February after all. 

Several weeks later the unimaginable happens. Willa is walking home one day when she approaches the site of a horrific trolley accident. Dr. Winston has been killed while attempting to push Simon Cleery out of the way of the speeding trolley. Willa returns home in shock, where her entire family is waiting for her, having learned from the new parish priest that Willa and Paddy have NOT been going to the soup kitchen. 

Willa's parents are taken aback when Paddy announces he plans to join the church. Willa tells her parents about the Dr's death and tells them she will join the convent. But when she goes to speak with the Mother Superior she feels  panicked about the entire situation. On the way home, a man approaches her. He is Dr. Winston's husband, and he tells Willa Dr. Winston left money for Willa to attend medical school, which Willa declines explaining that . Willa returns to the field hospital at the bridge to gather some of the Doctor's final things when there is a catastrophic collapse and 12 men are thrown into the sea, including Sam. 

Willa helps save their lives but gets her photo taken for the newspaper, which makes her mother LIVID. She confronts Willa but to Willa's immense surprise the rest of her family takes her side, explaining to their mother that Willa is meant to be a doctor, not a nun. Even the parish priests agree, Willa's heart is simply not on the church. 

Several months later, Willa and Sam are officially in a relationship when the Golden Gate opens for traffic. Willa plans to start medical school, and Sam plans to stay with her in San Francisco.