I have no idea who this Paola Visconti was.
From pnsintra.imc-ip.pt/pt-PT/coleccoes/pintura/ContentDetail.aspx?id=218; a veiling reflection in the lower part of the right side was removed with Photoshop by gogm.
This undated portrait of Paola Visconti shows that Italian dress was much more relaxed than Spanish, French, or other counterparts.
Keywords: Bordoni, Paola Visconti, straight coiffure, cap, vee neckline, partlet, collar, crescent neckline, rolled sleeves, slashed sleeves, girdle, shallow vee waistline, close skirt, under-skirt, gloves, necklace, fan