Roisin Mullen was a featured speaker at StopCyberbullying 2015 held this week in Limerick and Dublin.
Mullen created an initiative called Post-It Positive, encouraging schools to get students and teachers to write positive messages to each other on Post-It notes.
"You put something nice on a Post-It note, and give it to other people so they won't become a bully," she explains.
The summit involved children and adults from across North America and the U.K., as well as industry officials from Facebook and Google.
Roisin travelled to Ireland with her mother Heather, who was also one of the organizers.
"With Post-It Positive we can start the conversation earlier than the age of 12, so that these kids have skills before they go online," said Heather Roisin.
"They are the digital natives, and they understand the technology first. The students walked away being really surprised at how much their voices were important to industry."
Roisin and Heather also visited St. Dominic's Secondary school in Dublin to help create a Post-It Positive wall, which the school plans to keep permanently.