At the time, Phoenix was booming and the housing market was growing manic. Ms. Taylor soon found her niche as a mortgage loan officer, bringing home commissions large enough to rent a house and live comfortably. She reconnected with Mr. Duncan, whom she had met while in the Air Force, and in 2004, their daughter was born.

The overheated mortgage market in Phoenix was banking on the continued rise of home values. But after mid-2006, those values began to decline, making refinancing impossible for Ms. Taylor’s increasingly desperate clients.

In 2008, after the death of her grandmother, with whom she was close, Ms. Taylor quit her job, she said, to give herself time to regroup. But she never regained her economic footing. She spent down her savings, only to find that the customer-service and phone-sales jobs for which she qualified were paying less than before and were harder to come by. “I had to downgrade to an apartment; it got difficult paying day care, apartment, car payments, insurance — all the basic needs in life,” she said.

Although the number of low-wage jobs has grown nationally since the recession hit, their rebound has been slow in Arizona, while middle-wage jobs in health care and finance, particularly the insurance industry, have led the recovery, said Lee McPheters, an economist at Arizona State University. In inflation-adjusted terms, he said, customer-service jobs pay less than they did before, and the state’s unemployment rate of 6.9 percent is still above the 6.3 percent national average.

Eventually, Ms. Taylor applied for food stamps and Medicaid. In January 2010, in an attempt to improve her prospects, she enrolled full time at Estrella Mountain Community College, with plans to major in engineering. Ms. Taylor’s daughter went to day care and Ms. Taylor’s mother and stepfather helped care for her.

In late 2011, Ms. Taylor and Mr. Duncan had a son and were living together as a family. But they couldn’t afford rent and so they moved to a “weekly,” a cheap motel that is often the last stop before homelessness. Ms. Taylor was working in customer service, making $12.35 an hour. To keep her student loan debt — now about $30,000, she said — from ballooning, Ms. Taylor tried to pay for her own classes, but eventually took a break from school in mid-2012.

When money became even tighter, she and the children stayed with her parents. In 2013, her work hours were cut and she lost a child-care subsidy she’d been getting. She became pregnant with her younger son, was placed on bed rest, and during her absence she was fired, she said. By the time she was arrested, she said, she was filling in as an office aide at a home health care agency for about eight hours every other week. She was paid $8 an hour in cash, she said. (The agency said Ms. Taylor had not worked there — she had been offered a job, the human resources manager said, but she had not taken it because she could not find child care.)