From what little I can find, the Strozzis were musical and the Costagutis were aristocracy, including Cardinals.
From Wikimedia.
Isabella's dress has that portrait studio casual flair to it. She uses pink ribbons to adorn the sides of her hurluberlu coiffure.
Keywords: Voet, Isabella Strozzi Costaguti, Strozzi family, Costaguti family, Italian, hurluberlu coiffure, hair jewelry, ribbon headdress, rosettes, off shoulder scoop neckline, chemise, modesty piece, elbow length full under-sleeves, lace cuffs, over-dress, drapery, elbow length notched full sleeves, necklace, earrings, brooch, clasps