Quality Street (1927)

A young British doctor leaves his fiancé to go off and fight in the Napoleonic wars. Upon his return ten years later, he finds the the beautiful young girl he knew is now a tired, aging schoolteacher and he is no longer interested in her. She is still in love with him, however, and rather than give him up, she "reinvents" herself as her younger, perkier "niece" Livvy and tries to regain his interest.