Her genealogical sketch is here. She died in 1842, not long after this portrait was painted. She bore her first child in December 1837, so I am guessing this id from January 1837 or earlier. She bore a son and then a daughter.
From pinterest.com/anavegamedina5/retratos-de-federico-de-madrazo-y-kuntz/. Also posted to the Iberian Style in the Revolutionary Era Album here.