Home visiting is an attempt to counter the damaging effects of poverty by changing habits and behaviors that have developed over generations. It gained popularity in the United States in the late 1800s when health workers like Dr. S. Josephine Baker and Lillian Wald helped poor mothers and their babies on the teeming, impoverished Lower East Side of Manhattan. At its best, the program gives poor women the confidence to take charge of their lives, a tall order that Ms. Pletz says can be achieved only if the visits are sustained. In her program, operated here by Le Bonheur Children’s Hospital, the visits continue for two years.

It is Ms. Pletz’s knack for listening and talking to women — about misbehaving men, broken cars, unreliable families — that forms the bones of her bond with them.

She zips around Memphis in her aging Toyota S.U.V. with a stethoscope dangling from the rearview mirror. Her cracked iPhone perpetually pings with texts from her 25 clients. Most of them are young, black, poor and single. Few had fathers in their lives as children, and their children are often repeating the same broken pattern.

“I was lost, going from house to house,” recalled Onie Hayslett, 22, who was homeless and pregnant when she first met Ms. Pletz two years ago. Her only shoes were slippers. “She brought me food. That’s not her job description, but she did it anyway. She really cares about what’s going on. I don’t have many people in my life like that.”