Her article in thepeerage is here.
From artuk.org.
This shows the tricuspid 1630s bodice as being a vest flanking a basque-ended stomacher.
Keywords: van Dyck, Elizabeth Cecil, Elizabeth Cavendish, Countess of Devonshire, Cecil family, Cavendish family, curly coiffure, earrings, necklace, vest bodice, elbow length puffed sleeves, flared cuffs, under-sleeves, forward-back flared cuffs, arm bands, stomacher, trapezoidal neckline, ribboned brooch, waist band, bows, natural high waistline, basque waistline, close skirt