The Wikipedia and thepeerage articles for George Ferrers Townshend have nothing to say about her.
From bbc.co.
Jane wears a delightful 1830s evening dress with a lace bertha over a lace stomacher panel that complement lace engageantes.
Keywords: Lawrence, Marchioness Townshend, Townshend family, Marquise, British, neo hurluberlu coiffure, jeweled feathered headdress, off shoulder ve neckline, lace bertha, elbow length notched upper puffed sleeves, lace cuffs, stomacher, lace, vee waistline, full skirt, necklace, brooch, bracelets, fan, lace wrap