From what I can find in Geneall.net, this may be Gabriela Caballero y Rebollo or, more likely, Rosa Rebollo y Rico. Gabriella was born in 1788 while Rosa's birth date is not listed.
Upgrade image posted 28 July 2016 from bjws.blogspot.ca/2014/09/women-by-spanish-painter-francisco-jose.html.
The Marquesa de Caballero wears a post-Napoléonic Empire dress with a separate bodice that appears to be made with brocade and a characteristically Spanish floral headdress as well as a jeweled comb or other hair ornament.
Keywords: 1807, Goya, Marquesa de Caballero, Marquise, Spanish, hair jewelry, floral headdress, square neckline, modesty piece, bertha, quarter length close sleeves, forward-back flared engageantes, waist band, Empire waistline, close skirt, necklace, earrings, cameo, bracelets, fan