Her admitted frauds total $861,000. DuBois scheduled sentencing for April 27.
Walker originally pleaded not guilty to the charges of stealing from the school and defrauding Wilmington Savings Fund Society.
She and Hugh C. Clark, a New Media founder and former board president, had been scheduled to go on trial in federal court April 2. As part of Walker's plea, she has agreed to cooperate with federal investigators and testify against him.
In November, a grand jury charged Walker and Clark with providing false documents to obtain a $357,500 loan from the bank in 2006, then defaulting on $339,000 of the debt.
The loan, which was obtained in Walker's name, was used to buy a commercial property at 22-24 E. Mount Airy Ave. for "their failed business venture, the Black Olive restaurant," the indictment said.
The two allegedly provided fake lease agreements to the bank featuring overstated rental revenues and "false or forged signatures" of renters; misrepresented income and cash flow of a rental property owned by Walker and occupied by Clark; and submitted a false tax return misrepresenting Walker's finances.
Last spring, a federal grand jury returned a 27-count indictment alleging that Clark and Walker stole $522,000 intended for the New Media charter to pay expenses at Lotus Academy, a small private school they controlled; to fund personal businesses, including the Black Olive and a nearby health-food store; and for personal expenses, including meals and credit-card bills.
Clark, a lawyer, helped found Lotus Academy, a private school in West Oak Lane, in 1974. He also helped establish New Media in 2004. He presided over the boards of both the charter school and Lotus Academy.
Walker, who told the judge she had received a doctorate in African American studies from Temple University in 2001, had been the top administrator at Lotus Academy and earned less than $30,000. When New Media opened, she became the charter school's founding CEO, and her salary averaged $100,000.
Even after New Media opened, Walker continued to serve in an "unpaid" executive position at Lotus and controlled the bank accounts of both schools.
In the plea agreement she signed Friday, Walker stated that "acting at the direction of Hugh Clark," she had "abused her position in various ways to enrich Walker and Clark and advance their personal interests."
The initial criminal charges were filed against Walker and Clark nearly two years after The Inquirer reported allegations of fiscal mismanagement and conflicts of interest at New Media, which has campuses in the Stenton and Germantown neighborhoods.
The Philadelphia School Reform Commission, which oversees charter schools in the city, forced both Walker and Clark to step down and sever all ties to New Media as conditions for renewing the school's operating charter in 2010.
The commission also required that all members of the charter board be replaced.
Walker said in court Friday that she has not been employed since a consulting position with New Media ended in June 2010.
New Media has 450 students in grades five through 12 and continues to operate under new leadership.
The school is the fourth Philadelphia charter school in whose administrators or board members have faced federal fraud charges in the past decade. Sources have said that the school is among at least 18 charter schools in the region that have come under federal investigation since 2008.
Contact staff writer Martha Woodall at 215-854-2789 or firstname.lastname@example.org.