Prosecutors said Ms. Pugh used the money from the book deals for her political campaigns, and to buy and renovate a house in Baltimore.

Ms. Pugh did not recuse herself from voting or other decision-making on issues related to companies that paid her for the books , including health care firms, and had not disclosed the financial relationships publicly, the indictment said.

The tumult over the “Healthy Holly” books came as Baltimore veered from one crisis to another in recent years. The city has cycled through five police chiefs in four years, contended with stubbornly high homicide rates, and sought to reform a Police Department that is operating under a federal court order intended to end discriminatory practices.

Prosecutors also revealed on Wednesday that Gary Brown Jr., who served as an aide to Ms. Pugh in the State Senate and at City Hall, had pleaded guilty to fraud and for filing a false tax return. Prosecutors said Mr. Brown and Ms. Pugh worked from 2011 to 2019 in a “scheme to fraudulently sell and distribute tens of thousands of ‘Healthy Holly’ books.” They said the two provided books to purchasers but then “converted them to their own use at campaign events and government functions.”

Roslyn Wedington, the executive director of a nonprofit group that was once led by Ms. Pugh, also pleaded guilty to defrauding the government and filing false tax returns. Prosecutors said Ms. Wedington, who had led the Maryland Center for Adult Training, a job training program, knowingly filed false tax returns that had been prepared by Mr. Brown.

On at least one occasion, children’s books bought by the University of Maryland Medical System — a health care nonprofit organization with extensive business dealings with the city — and promised to public schools instead went to one of Ms. Pugh’s offices and were later used “as giveaways to promote her political campaigns,” according to the indictment.

In other cases, thousands of copies of “Healthy Holly” were never printed at all, according to the indictment, even though the medical system paid Ms. Pugh $200,000 for them on the condition that they be donated to schoolchildren.