Blessed Marie Droste zu Vischering, Sister Mary of the Divine Heart (1863 - 1899) whose revelations from Our Lord were instrumental in Pope Leo XIII's decision to consecrate the world to the Sacred Heart of Jesus in 1899.
https://www.ncregister.com/blog/a-forgotten-blessed-nun-who-influenced-the-pope "Then on June 4, 1898, she revealed to her confessor: “The Lord gave me the directive to write to the Holy Father with the request to dedicate the whole of humankind to the Sacred Heart.” It was extraordinary, but not unusual because for her entire life she had a fervent devotion to the Heart of Jesus. “She saw this Heart as the light illuminating the whole world, as an ocean of love, of compassion and kindness,” explained her congregation’s biography of her. Sister Mary of the Divine Heart called herself the “Apostle of His Heart.”
There are so many.Who can keep count? St Padre Pio was himself Spiritual Director to dozens and dozens of them, all of them Saints and Mystics.