Can widows or widowers become nuns and priests in the Catholic Church?
Yes, widowers and widows frequently enter the priesthood/religious life. The Sacrament of Holy Matrimony is only binding until the death of one spouse. At that point, the surviving spouse is free to enter into either the Sacrament of Holy Matrimony with a second spouse -OR- to receive the Sacrament of Holy Orders and become a priest or take orders to become a religious sister. Virginity is NOT a prerequisite for either the priesthood or the religious life in any way. Say a young man engaged in illicit sex from the age of 16 to 22 without marrying, then had a religious awakening and was called to the priesthood. His sexual experiences would require repentance, but he would not be rejected from the priesthood simply because of that. Of course, his priestly formation would have to have an extra facet because he isn’t giving up something he’s never experienced, like a virgin fellow would, but this complication is not insurmountable.