Excellent to see the quality of this! Thanks!
Henriette Wyeth Hurd (October 22, 1907-April 3, 1997), the eldest daughter of illustrator N.C. Wyeth, was an American artist noted for her portraits and still life paintings.
Biography on Wikipedia: https://en.wikipedia.org/wiki/Henriette_Wyeth
Andrew Wyeth by Henriette Wyeth
1956 / Oil on canvas / 17-5/16 x 15-3/16″ / National Portrait Gallery, Smithsonian Institution, DC
Henriette Wyeth on Artnet: http://www.artnet.com/artists/henriette-wyeth/