Her article in thepeerage is here. The original Reynolds follows this image.
From nationaltrustcollections.org.uk-object-979734; size adjusted to 30 cm high at 28.35 pixels/cm.
Lady Margaret is shown wearing a capelet over her bodice and fichu in this print.
Keywords: Reynolds, Smith - John Raphael, Margaret Willes, Lady Beaumont, Willes family, Beaumont family, British, straight coiffure, cap, fichu, high vee neckline, capelet, ruffles, lace