Her article in thepeerage is here.
From bbc.co.
Lady Ellison's coiffure has a drop of hair in front of her ear, suggesting this portrait is from about 1840.
Keywords: Lucas, Isabella Caroline Ellison, Baroness Vernon, Ellison family, Vernon family, Baroness, British, straight coiffure, headdress, chignon, off shoulder vee neckline, three quarter length close sleeves, engageantes, lace, wrap, full skirt, floral bodice ornament, bracelets, handkerchief