(AP Photo/Alessandra Tarantino, Pool) Sister Veronica Openibo, right, stands next to Chicago Archbishop Cardinal Blase J. Cupich, left, and Father Tomaz Mavric, center, as they wait for Pope Francis to arrive at the third day of a Vatican's conference on dealing with sex abuse by priests, at the Vatican, Saturday, Feb. 23, 2019. The prominent Nigerian nun has blasted the culture of silence in the Catholic Church that has long sought to hide clergy sexual abuse, telling a Vatican summit that transparency and an admission of mistakes is needed to restore trust.