Lady Margaret Graham wears a saya-type dress with hanging sleeves and fakse sleeves, but with a much modified muff in this 1626 portrait by Adam de Colone. Her article in thepeerage.com is here.
I cannot find much about Adam de Colone other than he was Scottish.
It looks like she endured a bad hair day. This is another example of a ruff combined with modesty piece and bertha.
Keywords: 1626, de Colone, British, feathered lace headdress, square décolletage, ruff, bertha, back flared cuffs, lace, tabbed sleeves, hanging sleeves, false sleeves, long close sleeves, vee waistline, full skirt, under-skirt, bracelets, brooch, girdle, fan