Jessica Brennan, who was Allan Brennan at the time of offending, preyed on the young victims between 1998 and 2016 when they were of school age.
The victims bravely came forward to speak to the police and tell of their horrific ordeals.
Brennan, 54, was questioned by detectives but denied any knowledge of the offences, putting the victims through the ordeal of a trial.
The jury at York Crown Court saw through her lies and found her guilty of a number of sexual assaults.
Brennan was sentenced to 22 years in prison at the same court on Monday after she was convicted of attempted rape of a child under 13; assault of a girl under 13 by penetration; five counts of sexual activity with a child; assault by penetration; two counts of sexual assault; sexual activity with a child; and five counts of indecent assault.
Brennan of Bowland Close, Harrogate was also ordered to sign the sex offenders register for life and handed an indefinite Sexual Harm Protection Order, which will place strict restrictions on her when she is released from prison.
Detective Constable Rebecca Prentice of North Yorkshire Police’s Harrogate & Craven CID said: “The victims in this case, and their families, have had their lives shattered by this vile and dangerous paedophile
“But they have shown incredible bravery coming forward, some after 20 years, and their courage has ensured that Brennan has been put behind bars where she belongs for a very long time.
“It’s never too late to report sexual abuse and if you have been a victim there are various ways you can report to police.
“You can call non-emergency number 101, go to a police station or speak a support agency or charity listed on our website if you do not wish to speak to us. Always call 999 in an emergency.”