This is 'Marguerite', painted in 1918 by the American Impressionist Guy Orlando Rose (1867-1925). Born in California, he studied art in Paris, and bought a cottage in Giverny where he and his wife lived for eight years, becoming friends with Claude Monet.
I'm fairly sure I've posted this before, but I don't keep a record and anyway it's pleasing enough to deserve a second showing.