Chinese Song Ceramic Stem Cup

Chinese, likely Song Dynasty, ceramic cup with a white glaze and a small, slightly flared stem. With a letter of provenance. Provenance: Purchased in May, 1930 by Aganetha Helen Fast (American, 1888-1981), a missionary. Height: 2 3/4 in x diameter: 3 1/2 in. Condition:There are no major chips, cracks, or losses. Light wear throughout as expected.