Jimena's origin has been subject to scholarly discussion and debate. Her patronymic indicates that her father was named Munio, and a contemporary chronicler, Bishop Pelagius of Oviedo, called her nobilisima, while the Crónicas anónimas de Sahagún describes her similarly, muy noble. The 17th century historian Luis Alfonso de Carvallo made her sister of Galician count Rodrigo Muñoz and daughter of count Munio Rodríguez by his wife Jimena Ordóñez, granddaughter of king Bermudo II of León. In this he was followed the next century by church historianEnrique Flórez, but both the chronology and the politics would seem to militate against this placement. She would appear to be the woman of this name in charters of the monastery of San Pedro de Montes along with a Munio Muñoz and his wife Velasquita. With Munio appearing to be too old to have been her brother, historian Quintana Prieto suggested that these were Jimena's parents. He likewise suggests that Munio was the count of this name who accompanied Alfonso to Seville. Other historians have accepted this relationship, and further, have made Munio Muñoz a son of Munio Rodríguez and Jimena Ordóñez, by which connection Jimena would be a descendant of Bermudo II. On the other hand, Canal Sánchez Pagín called attention to a Jimena Muñoz who was sister of Asturian count Rodrigo Muñoz, of Urraca Muñoz, wife of count Gómez González, and of Enderquina Muñoz, wife of count Fernando Díaz, all children of nobilisimi comitis Monio Gonçaluizi. He concluded that, among the possible solutions to the parentage of Jimena, it was most likely she was identical to the daughter of this count Munio González and his wife Mayor. In this he was followed by genealogist Szabolcs de Vajay and historian Jaime de Salazar y Acha, who further showed that a count Munio Rodríguez had two daughters by his wife Jimena Muñoz: Velasquita and Mayor Muñoz, and he also showed that the wife of Munio Muñoz was named Velasquita Muñoz. He concluded that the king's lover, Jimena, was daughter of Munio González and this Mayor Muñoz, making her niece rather than daughter of Munio Muñoz and Velasquita Muñoz. In his study of the bishops of Astorga, Quintana Prieto suggested that Jimena was a relative of bishop Pedro of Astorga, who was deprived of his seat in the early 1070s, and confined at the San Pedro del Montes monastery. The bishop's father was named Munio González. Jimeno would make donations both to the San Pedro monastery and to Astorga Cathedral, as well as to the Hospital de San Juan. Jimena is thought to have formed a liaison with Alfonso in the period between his first and second marriages, and she appears to have retired from court not long after the birth of her younger daughter and Alfonso's marriage to Constance of Burgundy. He would name his former mistress his tenente over Castillo de Cornatel in El Bierzo, a role she occupied from 1093 to 1108. She died in 1128.
Burial
Jimena would be interred in San Andrés monastery, Vega de Espinareda, in the El Bierzo region of León. Her grave, now lost, was once marked with an inscribed memorial stone that is now held by the Museo de León in that city.
Issue
By her relationship with Alfonso, Jimena Muñoz was mother of two daughters, both of whom would marry prominent counts.
