see Poland Street 1 to 9 & 49 to 62 in London Addresses dataset
Thomas Rowlandson DNB 1757-1827 lived at 50 Poland St from or before 1787 with his aunt Jane Rowlandson who had brought him up and a servant Mary Chateauvert. His aunt Jane died there April 1789 (her will PCC 1789), he had moved to the Strand by Christmas 1791 / ratebooks 50 Poland St 1789 Thomas Rawlinson / SunFire 1790 Thomas Rowlandson gent 50 Poland St
DNB says his companion and executrix Betsey Winter died in 1835 and that there is a drawing reputedly of her by him from the late 1780s. If she was the Elizabeth Winter of Round Court buried at Holborn 15.11.1835 age 52, then she may have been the Elizabeth Amabilis dau of Thomas & Elizabeth Winter bapt 8.10.1782 St James, (perhaps Thomas Winter mathematical instrument maker of 37 Brewer St, Golden Sq SunFire 179i) and would have been only a small girl in the late 1780s