LANSING, Mich. — Judge Rosemarie Aquilina listened on Monday morning as yet another gymnast, one of scores coming forward in her courtroom, took her turn excoriating Lawrence G. Nassar, a prominent doctor for U.S.A. Gymnastics who has pleaded guilty to multiple sex crimes.

The young woman finished, and Judge Aquilina, who has now allowed nearly 140 girls and women, including several prominent Olympic gymnasts, to give statements against Dr. Nassar, leaned forward from the bench. She smiled at the gymnast, Bailey Lorencen, and delivered her own heartfelt statement in a manner and tone befitting a therapist.

“The military has not yet come up with fiber as strong as you,” Judge Aquilina told Ms. Lorencen, calling her a “heroine” and a “superhero.” She added: “Mattel ought to make toys so that little girls can look at you and say, ‘I want to be her.’ Thank you so much for being here, and for your strength.”

Belying the stone-faced image of dispassionate jurists, Judge Aquilina has emerged as an unusually fierce victims’ advocate in a sentencing hearing that has drawn national attention for the scope of Dr. Nassar’s abuse and for the role that institutions like U.S.A. Gymnastics and Michigan State University played in employing him for decades.