Antonia de Anda Altamirano wife of Pedro Mexia

One of my sets of 10th great grandparents were Antonia de Anda Altamirano (allegedly de Viduarre) and Pedro Mexia (Mejia). Antonia and Pedro were married on 11 Dec 1650 by Father (licensiado) Don Alejo de Viduarri with the assistance of Juan de Contreras (y Fuerte ?). Pedro Mexia was the son of Marcos Mexia and Agustina de Medina; while Antonia de Anda Altamirano was the daughter of Pedro de Anda y Altamirano

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The witnesses were Juan Saes de Viduarri, his son Diego Ortiz Viduarri, and Juan del Castillo. No padrinos are listed.

Pedro de Anda Altamirano married Catalina de Viduarre on 28 Jul 1648, ergo Catalina de Viduarre cannot be Antonia de Anda y Altamirano's mother.... Who is her mother?