Count George of Nassau-Beilstein, later also Count of Nassau-Dillenburg, was the third son of Count John VI "the Elder" of Nassau-Dillenburg from his first marriage with Landgravine Elisabeth of Leuch
Elisabeth of Leuchtenberg was the elder daughter of Landgrave George III, Landgrave of Leuchtenberg and Margravine Barbara of Brandenburg-Ansbach.
Possibly Elisabeth van Leuchtenberg. She is wearing a dark dress with puff sleeves and rings on her index fingers.
Photo of a drawing. Collection Royal House of the Netherlands.