Vanessa George, 39, from Plymouth, took photographs on her phone of her abusing toddlers at Little Ted's Nursery.
The judge said she would serve at least seven years for her crimes which "plumbed new depths of depravity".
Angela Allen, 39, from Nottingham, who was sent the images, was told she would serve at least five years. She also received an indeterminate sentence. Colin Blanchard, 39, from Rochdale, who forwarded the pictures to Allen after George sent them to him, will be sentenced at a later date.
He dubbed George "wicked, cold and calculating" and told her: "It is in effect a life sentence."
He said neither George nor Allen would be allowed to be released while they remained a danger to the public.
"This case has cause widespread revulsion and incredulity," he said. "It has rocked the city of Plymouth but the shockwaves extend much further, perhaps to every nursery school in the country."
He told George: "You gave parents who entrusted their children to your care every reason to believe they would be safe. How grossly did you abuse their trust. What you did plumbed new depths of depravity."
As George was led out of court, two women jumped from their seats in the public gallery and screamed abuse at her. While another mother, who chose not to attend court, said: "Life wouldn't have been good enough."
Outside the court after the hearing, one father said: "It's brilliant to know that she's out of the way and can't harm anyone else. Hearing what was done to our babies, you end up with mental images. You can't sleep or eat. It affects your relationship but hopefully now we can start to rebuild our lives. I can go home tonight and cuddle my child knowing they are safe."
George has refused to give investigators a definitive list of her victims, despite pleas from some of the families.
Mr Justice Royce said: "I find it difficult to accept that she is genuinely not in a position to provide more information than she has." George's defence barrister had made her abuse sound as forgettable as "a cup of coffee", the judge said.
Mother-of-two George had admitted seven sexual assaults and six counts of making and distributing indecent pictures of children at a hearing in October. Allen admitted four child sex assaults and one count of distributing an indecent image, while Blanchard pleaded guilty to 17 offences relating to indecent images of children and two sexual assaults on children. He also admitted a further charge of possessing extreme pornography.
Police said they remained committed to identifying the children George abused. Detectives said the abuse started in December 2008 after the three apparently met on a social networking site.
George was arrested at her home in Efford in June this year after images of sexually abusing children and babies were found on a computer in Manchester.
Brb off to cuddle my baby sister.