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 "Conrad Reventlow")
ca. 1625 - 1673 (48 år)