His will contains a long list of bequests to his surviving sisters, and to his numerous nephews and nieces. The principal beneficiary was his niece Mary, daughter of his brother the Rev. Rowland Singleton, vicar of Termonfeckin, and his wife Elizabeth Graham, and sister of Charity Singleton Cope (1707-1779), who married Sir William Yorke as her second husband. Mary married Philip Tisdall, Attorney General for Ireland from 1760 to 1777, who was a dominant figure in the Irish Government for many years. Tisdall hoped to succeed Singleton as Master of the Rolls, but was passed over. Mary ("la belle Marie") was a noted beauty: she and Philip were both painted by the celebrated Swiss painter Angelica Kauffman.Registry of Deeds Dublin Abstracts of Wills Vol. 2
