Dorothy Demme, 81, who as a senior citizen became a character actress in movies directed by her son, Jonathan Demme. She made her on-camera debut a decade ago as a dancer in UB40's "I Got U Babe" video with Chrissie Hynde. Demme then had speaking parts in her son's hit films, first as a thrift store salesclerk in "Something Wild" in 1986, and continuing in small parts in "Married to the Mob" in 1988 and "Silence of the Lambs" in 1991. Her last performance was as a fussbudget juror in "Philadelphia" in 1993. For the past 25 years, Demme had logged about 5,000 hours as group leader of the Patient Assistance Volunteer Program at Southside Hospital in Bay Shore, N.Y. She also dabbled in woodcarving, sketching and multimedia sculpture. On Nov. 20 in West Islip, N.Y., of emphysema.