Magdalena Ross was the second daughter of William Ross, miniature painter, and Maria Smith, and younger sister of Sir William Ross, Miniature Painter to Queen Victoria. Trained as a miniaturist by her father, she exhibited at the Royal Academy from 1820  to 1856  and styled herself 'Miniature Painter to the Queen' from 1850. She also produced watercolour copies of her brother William's work for Queen Victoria, and some of these remain in the Royal Collection. A miniature of her by Sir William Ross is in the Victoria and Albert Museum, London (281-1875).

Sir William Ross's appearance is easily corroborated; two youthful self-portraits of c.1815 (Bonhams, London, 10 April 2002, lot 422) and c.1820 (Victoria and Albert Museum, London: no. 1383-1874) are known, as well as an oil portrait by Thomas Henry Illidge (1799 – 1851) of c.1846 identified from an engraving reproduced in the Art Journal, 1849, I, p. 48. The only photograph of him, showing him in old age, is also in the Royal Collection (2906837). However, Ross's appearance in this miniature is closest to that in a miniature of him by his older brother Hugh Ross (National Portrait Gallery, London: no. 1946) of c.1843, and can therefore be dated to that period.

Inscribed on the reverse in ink: Sir Will / Ross / by his sister / Mrs. Dalton.