Her genealogical article is here. She was born a von Ostfriesland and married a von Ostfriesland. Ostfriesland abuts the northern end of The Netherlands.
From the Sotheby's Web site; flaws, smudges, and spots removed throughout image with Photoshop. Also posted to the End of the Era - 1684 to 1715 Album here.
The Princess appears to be wearing a white negligée under her corset under a clasped changeable fabric over-garment.
Keywords: 1707, van der Zijpen, Princess Marie-Charlotte von Ostfriesland, comtesse de Criechingen, von Ostfriesland family, Princess, Countess, German, wavy coiffure, earrings, chemise, U-neckline, modesty piece, corset, square neckline, over-garment, clasps, close skirt, wrap