Doña Mafalda

It is worth mentioning the young Infanta Doña Mafalda (1191-1204), daughter of Alfonso VIII and Leonor de Plantagenet, who died at the age of thirteen in Salamanca. The young girl was buried in the Old Cathedral, next to the main altarpiece presided over by our patron saint, the Virgen de la Vega.

Source: https://curiosidadesdelahistoriablog.com/2020/11/23/urraca-de-leon-c-1080-1126-el-complicado-reinado-de-una-mujer-en-la-edad-media/
More info: https://catedralsalamanca.org/catedral-vieja/