The Hon. John Smith-Barry was the youngest son of James, 4th Earl of Barrymore (d.1747) (see lot 4) and his 3rd wife Anne (d.1753), youngest daughter of Arthur, 3rd Earl of Donegall. In 1747 John Smith-Barry succeeded to his father's unsettled estates, which were considerable, including Marbury Hall, together with extensive lands in Cheshire, and Fota Island with extensive land in County Cork, Ireland. In 1746 he married Dorothy (see lot 2), daughter and co-heir of Hugh Smith of Weald Hall, Essex (see lot 1), through whom large estates in Tipperary, Louth and Huntingdonshire entered the family. He had two sons by this marriage: James Hugh (b.1748) and Richard. The former, who inherited Marbury on the death of his father, went on the Grand Tour in 1776 and formed a notable collection of pictures and antiquities at Marbury.

Haytley painted a portrait of The Hon. John Smith-Barry and Mrs. Smith-Barry with their two sons, James and Richard. The present portrait depicts a young girl identified as Catherine Smith-Barry, in an interior at Marbury. Catherine had an elder sister, Anne Dorothy (1748-1797) and they are both buried at Budworth, Cheshire.