According to the book “Privatissimo – Kunst aus Schleswig-Holsteinishem Adelsbesitz” it is the portrait of Agnes Gräfin von Reventlow geb. von Hammerstein-Loxten.
But on the backsite of the picture is a note saying: "Auguste Gräfin Holck. Gemahlin des Henning Bendix von Qualen auf Damp."
burial place of Claus Reventlow (1693-1759) and his wife Charlotte Dorothea nee von Plessen (+ 1789). The marble sarcophagus is the work of Simon Carl Stanley
.jpg "Reventlow, Christian Ditlev Frederik 1746-1827")
ca. 1466 - 1571 (105 år)