"She was a bit jealous and started spreading all these rumours about me - that I was a slut, and that when I moved here I got around with all these guys, and all this other stuff," Layla said.
A few weeks later the other girl and two friends approached her on the playing fields and accused her of saying things about them. She denied it, but after that those girls started shoulder-bumping and tripping her.
Near the end of the second term last year, Layla spotted the girls while shopping in Pukekohe with her mother. Mrs Bartlett went over to them and asked which one was the main bully.
"They got quite nasty," she said. "As me and my oldest daughter were talking to them, my daughter [Layla] came over. They not only tried to get my daughter right there in front of me, they tried to get me as well."
Layla said: "They got really, really nasty, saying they would get the Black Power on to me, because one of the girls' uncles is a member."
She stayed away from the school for the next term and enrolled for a short time at Edgewater College in Pakuranga.
She came back to Pukekohe High for one day in the fourth term but left again because she still feared the bullies. Layla moved to Tuakau College this year, and has not been bullied since.
Mrs Bartlett has set up a Facebook page, Take a Stand Against Bullies, for other families.
Pukekohe High board of trustees head Angela Clark said the girls who bullied Layla "went through a disciplinary process" and one left the school before the process was completed.
She said Layla saw the school counsellor and was required to be in class for her own protection.
"She was truant often and put herself at risk through doing that," Mrs Clark said.
The school trained students to be "peer mediators" and had signed an agreement with the local police to share information about bullying.
Mrs Clark said the board took "a very hard line" when it occurred.
VIOLENT TIMES
* Pukekohe High, a mid-decile school of 1600 children, was in the news late last year when a group of boys pulled down a boy's pants and tried to violate him with a vehicle part. Three boys were expelled for their part in that assault.
* Last week two girls were expelled for fighting each other after a Facebook dispute which started with disparaging comments made about a relative of one of the girls.