After the Infanta Isabella's death, the abbess of the English Benedictine Monastery in Brussels recorded her memories of the Infanta's interaction with the monastery and with other English Catholic exile foundations
Arblaster, P. (1997). The Infanta and the English Benedictine Nuns: Mary Percy’s Memories in 1633. Recusant History, 23(4), 508-527. https://doi.org/10.1017/S003419320000234X (Original work published 1997)