In 1947, Marie-Louise Pailleron, the daughter of the famous playwright Édouard Pailleron, wrote a memory book which revisited the portrait that the painter John Singer Sargent had done of her and her brother in 1881, when they were children. Although it is not unknown, this testimony has never been studied closely. This document throws valuable light on the child's perception of his condition as a model at a time when social expectations hypercathected the child portrait, a genre that enjoyed its golden age in the nineteenth century. It enriches our understanding of the close links between educational values and aesthetic ideals, between the model child and the child-model. Furthermore, through the sociability network to which the family of the model belonged, close to Jean-Martin Charcot, it raises the question of the relations between pose and hypnosis. Finally, it also invites comparisons with the novels that the contemporary and friend of Sargent, Henry James, devoted to the relations between adults and children.