She became Regent of a Monestary at age 5 and never married. Her German Wikipedia article is here.
From Wikimedia; image enlarged by half by gogm.
Ulrike Sophie wears a French-influenced dress and coiffure in this 1765 Matthieu portrait. She wears a fob watch.
Keywords: 1765, Matthieu, Ulrike Sophie of Mecklenburg-Schwerin, Mecklenburg-Schwerin family, German, high straight coiffure, ribbon headdress, square neckline, modesty piece, lace, revers, stomacher, bows en échelle, elbow length tight sleeves, engageantes, panniers, neck band, bracelets