[5] She was described by her brother, the 2nd Earl of Upper Ossory, in the most glowing terms:[6] "Lady Holland was the most amiable person that ever lived.

[4][9] Her portrait by Batoni, which depicts her in a grey silk Brunswick gown trimmed with striped ribbons, is considered one of his masterpieces.

[10] While in Rome, she also met Piranesi, who 11 years later dedicated a plate to her in his 1778 collection of engravings, Vasi, candelabri, cippi, sarcofagi, tripodi, lvcerne ed ornamenti antichi.

[11][4] A miniature of Lady Mary Fox after Reynolds, painted on an oval ivory plate, is in the collection of the Tsarskoye Selo State Museum in Saint Petersburg.

It was first publicised in 2018, when the artist was revealed to be English painter Edward Miles, who created the miniature during his 1772–92 apprenticeship with Reynolds.

In 1797, Miles brought the miniature to the court of Saint Petersburg, apparently as an example of the quality of his work, with a letter of recommendation from the Russian Ambassador Count Semyon Vorontsov.