Mary Cecilia of Jesus, OCD, born as Natividad Zialcita, (7 September 1908 – 13 December 1982) was a Discalced Carmelite nun and prioress of the monastery in Lipa during the time apparitions of Our Lady Mediatrix of All Graces in 1948.

Zialcita eventually heard Castillo's reports that she was being visited by a devil and the apparition and requests of a beautiful lady in her cell.

Zialcita also reportedly became a recipient of interior locutions from the Blessed Virgin Mary, who instructed her how to assist Castillo in fulfilling her requests.

[3] The apparitions became later known in public through news about miraculous healings, heavy fragrance of roses, the shower of rose petals that bore images of Jesus, Mary and religious scenes, the appearance of the blue bird and the spinning sun like what happened in Fatima, Portugal.

In February 1982, the Jesuit Federico Escalar of Ipil gave them a retreat, during which she was released from the ban of silence that had been imposed to her as well as to other witnesses of the apparitions in 1948 by the Apostolic Nunciature Egidio Vagnozzi.