According to her article in thepeerage, she was a Campbell who married a Campbell.
From the National Galleries of Scotland Web site.
Lady Juliana's dress is passé. But the center portion of her ruff and cuffs appear to be made of sophisticated lace and her waistline is in keeping with those worn by Queen Henrietta Maria.
Keywords: 1633, Lady Juliana Campbell, Campbell family, British, high straight coiffure, framing headdress, hair jewelry, high enclosing neckline, ruff, lace, over-dress, tabbed sleeves, puffed false sleeves, back-flared cuffs, natural waistline, bows, basque bodice, fan