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A pre-school teacher was sitting on a Southwest flight from Seattle to San Jose when something caught her eye. The passenger, in front of her, was having a disturbing text message conversation about children.

"I still get very choked up about it. It still hits hard," said Christina, a mother who has been a preschool teacher for almost three decades. Perhaps that is why when it comes to protecting children, her radar may be stronger than most.

She asked not to reveal her identity to protect her from retribution.

Christina remembers the man who was one row in front of her leaning his chair back and starting texting someone.

A few words caught her eye.

"I was looking out the window diagonally and just seeing the words "child in their underwear" alerted me," she said. "I don't know if it was divine intervention or what but I just saw that. What I saw unfold was horrifying and decided something had to be done."

Prosecutors claim 56-year-old Michael Kellar, was texting with 50-year-old Gail Burnworth. The two allegedly typed back and forth their plans to sexually abuse two children ages 5 to 7 and videotape it.

Discreetly, Christina used her phone to gather evidence.

"I just started taking pictures, zooming in and taking pictures," she said. "Just did it really quick and just did shot, shot, shot, shot."

As the plane began its descent, Christina made eye contact with a flight attendant.

"She asked if I was okay. And I leaned over and whispered I think there is some sort of pedophile action going on," Christina remembered. "[She] told me I would be the first off the plane to talk to their special ops person. And I showed him the first text, the second text, and that was enough for him to say we need to tell the authorities here."

Detectives credit Christina with being proactive and discreet. Police boarded the plane taking Kellar into custody before he could delete the messages. They tracked down Burnworth in Tacoma.

"There is truth in "see something, say something." It's not a cliche," said the preschool teacher. "Within hours they were able to get those kids out of the home, and that was the most impactful thing."

How did she know to do all those things?

"I watch too much C.S.I.," she said laughing.

Kellar and Burnworth are charged with Attempted Enticement of a Minor and Conspiracy to Produce Child Pornography. If convicted, they face 15 to 30 years in prison.