Charlotte's article in thepeerage is here; Eliza's is here. There is no mention of whether they had children.
From the Sotheby's Web site; enlarged by half.
Charlotte's dress may have a lower waistline and longer sleeves than Elia's, but both have square necklines and close skirts.
Keywords: 1810, Reinagle, Charlotte Sullivan, Eliza Sullivan, Sullivan family, Hale family, Pleydell-Bouverie family, British, curly coiffure, square neckline, lone close sleeves, quarter length close sleeves, cuffs, Empire low waistline, waist band, Empire waistline, close skirt, wrap, clasps