The Irish star was tormented in the schoolyard when she was younger but would always report any teasing to her parents to ensure it did not get out of hand.
She fears the rise of the Internet has made it easier for thugs to target their victims, and she has signed up as a face of a Disney Club Penguin campaign to help cut out online bullying.
Healy tells Hello! magazine, "There are too many horror stories about young people driven to suicide after online bullying. It ranges from calling someone a 'spin-out', which I've just learned means 'stupid', to much worse things... That's why it's important for parents to teach their kids the rules of the online road, to tell them to treat each other kindly and to advise them how to be safe by not giving out private information...
"As a Twitter user, I've had to put up with the odd nasty comment, but I've developed the confidence to know it's just coming from a coward hiding behind a computer and I block them. Some people think when they're hidden behind a screen they can say what they want."