Her article in thepeerage is here. She was the daughter of Anne Clifford.
From blog.mam.org/2013/02/22/from-the-collection-margaret-lady-tufton-by-anthony-van-dyck-and-studio.
Lady Margaret's chemise appears to be made to match her bodice sewn to it in this 1632 van Dyck. This style would not change much for about 50 years.
Keywords: 1632, van Dyck, Glembin, Margaret Tufton, Cecil family, Tufton family, Bitish, curly coiffure, proto-hurluberlu coiffure, jeweled headdress, bun, chemise, elbow length under-sleeves, bodice, trapezoidal décolletage, elbow length puffed sleeves, slashed sleeves, girdle, natural high waistline, necklace, earrings, brooch, jeweled bodice, clasps, jeweled skirt ornament