John of Castle Milk, her uncle, left her £50, otherwise all that is known about her is from the book on Kings Lynn which says "she was held in great esteem in that town." She is also mentioned in Fanny Burney's diary.
Source: Robert Halliday Lidderdale, An Account of the Lowland Scots Family of Lidderdale, 1950.
Maria Georgiana Lidderdale's Last Will and Testament was written on April 9, 1785, and recorded on April 19, 1787, in London. The will names cousin Dorothy Young spinster as the beneficiary. Dorothy may have been the daughter of Christian Lidderdale (married Thomas Young), who was her father's sister. The will also names cousins Eleanora Hutton, Mary Lidderdale, Margaret Brown, and Elizabeth Williamson, all daughters of James Lidderdale, who was her father's brother.
Source: Public Record Office, The National Archives, United Kingdom (http://www.documentsonline.pro.gov.uk)