Right after his election to the Royal Academy a the minimum required age of twenty -five, Lawrence was given the commission for the portrait of Sarah Goodin Barrett Moulton. She had just turned eleven and arrived from Jamaica. The adolescent looks like she is about to perform a dance step in the wind, a wind ruffling her hair and blowing about the ribbons on her hat. She comes toward us, in front of a vast cloudy sky, looking at us with a candid expression (and an innocent ambiguity). The color of her dress explains the nickname Pinkie which at a very early date, as soon as it was painted, was given to the picture (and of course in contrast with Gainsborough's Blue Boy)
Nothing in this portrait foreshadowed the story's sad end: Pinkie died at the age of twelve, a week before Lawrence showed her portrait at the Royal Academy(at the time the work failed to win the huge popularity it still enjoys today).
(p158 of Only in America by Pierre Rosenberg)