This author-illustrator pair successfully continues the conceit of the child of a fictional 19th-century American painter living in Giverny, in Paris and now in New York. The pair’s attention to historical detail is utterly winning. For example, Charlotte’s entries in her diary about Monsieur Durand-Ruel’s auto breaking down in Giverny, the crossing on the ship Champagne from Le Havre or the Havemeyers’ ball in New York. Sweet uses collage, reproductions of the paintings mentioned and her own spirited watercolors to teach a few French words, supply a recipe or to illumine Charlotte’s comments about the artists’ colony in New Hampshire where her family goes to escape New York’s summer heat. It’s hard not to be charmed by her sending a packet of the new candy, “Good and Plenty,” to Monsieur Monet, who had asked for a souvenir. Fans will love to hear that Charlotte’s mama wants to have her portrait painted by John Singer Sargent, so the family will be going to England next. Brief biographies of all the real artists and patrons are appended. (illustration credits, author’s note) (Fiction. 8-12)