Lady Portman, appointed Lady of the Bedchamber on Queen Victoria's accession, and her children were popular with the young Queen. When Lady Portman's period of waiting was over on 2 October 1838, the Queen wrote in her Journal: 'Took leave of Lady Portman, (whose waiting is out) and of her dear children; which I did with extreme regret, as I'm very fond of her, and I shall miss the dear children sadly … Spoke [to Lord Melbourne] of Lady Portman's being gone, which I regretted so much, as also the departure of the dear children' (RA QVJ: 2 October 1838). Early the following year Queen Victoria commissioned Ross to paint a miniature of Louisa Portman. Sittings are recorded in the Queen's Journal on 11, 12, 13 and 14 February. By 15 February the Queen was able to report: 'Went to see Louisa sitting for her picture, which is now nearly finished and so pretty and like' (RA QVJ). On 9 March the Queen wrote: '[Ross] sent me the picture of little Louisa last night, which is charming' (RA QVJ). A copy was given by Queen Victoria to Lady Portman.

The Honourable Louisa Mary Portman, second daughter of Edward Berkeley Portman, 1st Viscount Portman, and Lady Emma Lascelles, third daughter of the 2nd Earl of Harewood. She died, unmarried, in 1870.

Signed, dated and inscribed on the reverse in ink (the inscription truncated): 1839 / [Pa]inted by / W.C. Ross ARA / Miniature Painte[r] / to / The Queen and in another hand 1839 / Hon: Louisa Mary P[ortman] […] 15. 1834