Lady Jane had two portraits painted by Reynolds, this one in 1775 and the one in the next image in 1776.
This is her article in thepeerage: "Jane Fleming F, #9523, d. 3 February 1824
Jane Fleming married General Charles Stanhope, 3rd Earl of Harrington, son of William Stanhope, 2nd Earl of Harrington and Lady Caroline Fitzroy, on 23 May 1779 at London, England. She died on 3 February 1824 at St. James's Palace, St. James's, London, England.
She was the daughter of Sir John Fleming, 1st and last Bt. and Jane Coleman. Her married name became Stanhope.
Children of Jane Fleming and General Charles Stanhope, 3rd Earl of Harrington
Hon. Charlotte Augusta Stanhope+ d. 15 Feb 1859
Hon. Caroline Anne Stanhope d. 25 Nov 1853
Maj.-Gen. Charles Stanhope, 4th Earl of Harrington+ b. 8 Apr 1780, d. 3 Mar 1851
Maj.-Gen. Hon. Lincoln Edwin Robert Stanhope b. 26 Nov 1781, d. 29 Feb 1840
Hon. Anna Maria Stanhope+ b. 3 Sep 1783, d. 3 Jul 1857
Leicester Fitzgerald Charles Stanhope, 5th Earl of Harrington+ b. 2 Sep 1784, d. 7 Sep 1862
Rev. Hon. FitzRoy Henry Richard Stanhope+ b. 24 Apr 1787, d. 11 Apr 1864
Major Hon. Sir Francis Charles Stanhope+ b. 29 Sep 1788, d. 9 Oct 1862
Rev. Hon. Henry William Stanhope b. 2 Aug 1790, d. 21 Jun 1872
Hon. Augustus Stanhope b. 25 Mar 1794, d. 8 Dec 1831."