Information about her is known from the Inquisition of her mother Isabel Ortiz in 1564 Isabel de Plazaola is revealed in those documents to have been a cantante y tañedora, who sang and accompanied herself and was paid for this activity in noble households, particularly the I(V Duquesa del Infantado in Guadalajara. She is known to have worked for the Marquesa de Távara in Alcalá de Henares, the Ci=ondesa de Coruña in Guadalajara, and Juana de la Lama, Duquesa de Alburquerque whose huysband as named governor of Milán. Plazaola was in Barcelona waiting to embark for Milan when her contract was canceled.