"It started over a football match in PE. It was over a goal," said Sarah.
She kept the bullying a secret from her parents.
"We didn't realise Sarah was being bullied until she lost her voice and we went to the doctors and that's when she admitted it," said her mum.
GMTV's medical expert Dr Hilary Jones said Sarah had lost her voice as a result of being picked on.
"If you are frightened that every time you open your mouth you will be ridiculed, eventually you can become withdrawn and stop speaking altogether," he said.
But it seems things are finally looking up for Sarah.
She's looking forward to going to a new college and would like to go to university in Liverpool - home of her fave footie team.