Prince Andrew has settled a federal sex-abuse lawsuit filed by Virginia Giuffre, one of Jeffrey Epstein’s most prominent accusers, according to a court filing Tuesday. David Boies, a lawyer for Ms. Giuffre, said in a letter to the judge that the parties had reached an agreement in principle, which court documents said would include Prince Andrew making a substantial donation to Ms. Giuffre’s charity. The filing didn’t indicate further financial terms of the settlement.