After deliberating for two days, a jury on Monday found Lyn Vijayendran, 36, guilty of the crime.
A judge sentenced the former principal of O.B. Whaley Elementary School in San Jose to two years of probation, $602 in fines and 100 hours of community service, which likely will involve training other educators in the proper reporting of suspected child abuse, the San Jose Mercury News reported.
"I agree with the jury's verdict," Santa Clara County Judge Deborah Ryan told a tearful Vijayendran. "You did what you thought was right, but I don't think it was objectively reasonable at the time.
"I know it will have far-reaching consequences for your career. I do think you made a very bad judgment that day," the judge said.
State law requires principals, teachers and others who come into contact with children to report suspected child abuse.
Child-abuse experts hailed the verdict after some thought the case would end in a mistrial.
A mistrial "would have sent the wrong message," said Margaret Petros, a commissioner on the Child Abuse Council of Santa Clara County. "This verdict is important for all mandated reporters to heed. There are so many who don't take it seriously."
After sentencing, Assistant District Attorney Alison Filo said Vijayendran simply did not meet her obligation as an educator and said as much during the weeklong trial.
"Getting talked out of that reasonable suspicion by her own inadequate investigation just isn't a defense," Filo said.
Vijayendran testified that teacher Craig Chandler appeared forthright when he told her an incident during which he allegedly blindfolded a second-grade girl and put something in her mouth was part of a lesson plan about Helen Keller.
Vijayendran's handwritten and typed notes say the second-grader told the principal that Chandler made her lie down on the classroom floor, touched her feet with something that felt like a tongue and put something in the 8-year-old's mouth that tasted like a salty liquid while she was blindfolded and alone with him in a classroom.
The notes also said Chandler wiggled her body and head back and forth and asked her earlier to open her legs.
Prosecutors said they decided to try Vijayendran because her failure to report the incident had bad consequences. Another child reported experiencing similar behavior by Chandler about three months later.
Chandler is now facing charges of committing lewd and lascivious acts on five children. A crime lab allegedly found his semen on a classroom chair.
He has pleaded not guilty and is scheduled to go to trial Dec. 5.
Vijayendran has been reassigned to the district office as a coordinator of teacher support programs. In a statement, the Evergreen School District said jurors had a difficult decision to make, but it was disappointed with the outcome. The statement did not elaborate.
After Vijayendran was sentenced, juror Susan LaGaffa said the ex-principal "stuck her head in the sand rather than pull the alarm. I think she didn't want this ugly thing to be true."
Another juror, Christina Rodriguez said: "There's a lot more people to be blamed for this. She's a good person - we all saw that."