She is believed to have had 200 sex sessions with the lads, aged 12 and 13 during that time.
Sister Norma was arrested by cops after victims James St Patrick, now 53, and Gerald Kobs, 55, "built up the courage over the years" to come forward.
"It's close to the end for us," the Sun quoted Mr Kobs, as saying.
It was also revealed that though Catholic bosses "learned of the situation" in the '90s, the only thing they did was order her to seek counselling.
Sister Norma on Monday changed her not guilty plea when she appeared in court. She could be jailed for ten years if found guilty of the crimes. She is set to return to court in Milwaukee, Wisconsin, on February 1.