If you know who Margalo Gillmore is and have seen her on the stage, you ight possibly be interested in the somewhat infantile memoirs of her childhood. Father Frank, a well-known thespian of his day, invited George Arliss to dinner and Founded Actors' Equity. Aunt Edith was an ardent theosophist who inspired delusions of witchcraft in young Margalo, while Granny and sister Ruth actually seem normal and generously unaffected by the ""flair"" for the dramatic. Even Margalo's little girl ranks proved her claim to an exaggerated theatrical fancy which was later channelled into the skills of an actress. This book brings teen-age Margalo through her first roadway success in ""The Famous Mrs. Fair"" and leaves the reader to wonder when and how she later grew up. The Gillmores' apartment was ""Four Flights Up"" and so too is the fantasy that assumes a general interest in this type of theatre memoir.