"Pinkie" by Sir Thomas Lawrence (1769-1830)
"Pinkie" was actually a portrait of Sarah Barrett Moulton painted when she was 11 years old. She was born in Jamaica, the daughter of a wealthy plantation owner, later she was sent to school in England. Sadly she died 1 year later after this portrait was painted of her, probably of tuberculosis. An interesting piece of trivia, Sarah had a brother Edward, he later changed his last name to Moulton-Barrett, and he became the father of the poet Elizabeth Barrett Browning.
Both of the paintings of "The Blue Boy" and "Pinkie" are on display near each other at "The Huntington" in San Marino, California. They are in a gallery of collections of 18Th century English portraiture paintings.