Here is her genealogical article.
From Wikimedia; filled in shadows about 40 % to bring out detail.
Marquesa Geronomia wears a brocade under-skirt beneath her somber black dress.
Keywords: 1624, van Dyck, Geronima Spinola, Geronima Marquesa de los Balbases, Doria, Doria family, Spinola family, Marquise, straight coiffure, jeweled feathered headdress, fitted bodice, deep ruff, high enclosing neckline, hanging sleeves, lining, long full false sleeves, contrasting ruffled cuffs, jeweled bodice ornament, full over-skirt, close under-skirt