When Mary O'Rourke leaves Ireland to visit her cousin Norah in New York, she finds that Norah and her baby have been deserted by her husband, John Stuyvesant. Mary goes to the aristocratic home of the Stuyvesants, where Mrs. Stuyvesant, an invalid, mistakes her for her son's wife. Warned that the woman could die from shock, Mary reluctantly assumes the role of daughter-in-law and nurses her back to health. Meanwhile, John and his cousin Fred return from a trip, and Genevieve Harbison, John's fiancée, demands that they get married the following day to prove that he is not married already. At the church, Mary produces Norah's marriage certificate, which John notices is for "John Frederick," Fred's real name. Fred then explains that his inheritance requires that he not be married until the next day. Genevieve angrily leaves after John agrees to play Fred's role, but when Fred sees Norah, he acknowledges the marriage. Mary then confuses Fred's trustee with Irish blarney and wins the legacy for Fred. She then accepts John's proposal. - AFI
The working title of the film was Mary O'Rourke . Originally titled "The Reign of Colleen O'Malley"