Grandmother, Mrs. H.P. Grattan (1810-1876), was also a well known actress.
Father: George Knottesford Fortescue (1847-1914), comedian; Mother: Viola Grattan Plunkett (1848- 1925), actress. (Father not to be confused with G. K. [George Knottesford] Fortescue, 1847-1912.).