Her Wikipedia article is here.
From ericab16's 1795-1816 Regency album on webshots.
Juliane wears a full skirt beneath a red wrap and long windswept hair in this Vigée-Lebrun portrait from about the time of her marriage to Grand Prince Constantine.
Keywords: 1795, Vigée-Lebrun, Juliane of Saxe-Coburg-Saalfeld, Wettin family, Romanov family, Princess, Grand Duchess, long curly coiffure, feathered hat, high neckline, collar, lace, wrap, full skirt