The single mother stood alone before the judge, trying to convince him she shouldn’t have to pay for an education her child never received.

Money was tight for Bianca Johnson, who was balancing a full-time job as an after-school care director with a full load of college classes in pursuit of a teaching career, and she had been counting on financial aid when she signed a contract to enroll her daughter at Sandy Spring Friends School. The private Quaker school, on a leafy campus in suburban Maryland, seemed like a perfect fit for her daughter, Teagan, a bubbly preschooler who was already starting to sound out words.