Ellen Rose Albertini Dow November 16 1913 May 4 2015 was an American film and television character actress and drama coach She portrayed feisty old ladies and may be best known as the rapping grandmother Rosie in The Wedding Singer 1998 performing Rappers Delight Dows other film roles include elderly lady Mary Cleary who outs her grandson in Wedding Crashers Disco Dottie in 54 the recipient of Christopher Lloyds characters slapstick in Radioland Murders and a choir nun in Sister Act She was best known to small screen audiences for her guest appearances on sitcom The Golden Girls Description above from the Wikipedia article Ellen Albertini Dowlicensed under CCBYSA full list of contributors on Wikipedia