A mother of three who waged a campaign of harassment against a former friend was today told she faces six months in jail if she does it again.

Donna Kavanagh, 39, fell out with Hayley Barber after problems between their children on a school bus on its way back to South Oxhey.

In May 2012 Kavanagh, previously of Markeston Green, South Oxhey, was fined £110 for hitting Hayley Barber outside the school. The two women had previously been friends and god mothers to each other's children, St Albans crown court heard.

Prosecutor Edward Colver said the day after the conviction, she began to harass Mrs Barber, leaving her scared and nervous.

"On June 19 2012 Mrs Kavanagh passed her in a car at traffic lights and shouted: 'You are going to be getting it soon'."

Mr Colver said: "There was a clear threat of violence. Mrs Barber had two children in her car and was terrified."

Then on March 7 last year Mrs Barber was waiting in Ainsdale Road when she saw Kavanagh in her Range Rover.

She drove past her and shouted: "You better be looking over your shoulder. I am coming for you. I am going to f....... kill you."

The next day she drove closely behind her.

Kavanagh now of Toms Lane, Kings Langley, pleaded not guilty to putting a person in fear of violence by harassment between May 3, 2012 and March 9, 2012, but was convicted by a jury.

Andel Singh, defending, said there had been no physical violence and no other offences since she was arrested.

"Mrs Kavanagh had moved out of South Oxhey and removed her child from the school. The chances of contact have been reduced."

He said Donna Kavanagh was estranged from her husband and was bringing up her three children, aged 13, 8 and 7.

Recorder Thomas Payne told Kavanagh: "You bore a grudge against Mrs Barber for a long time. Much of the conduct took place near junior school premises. I am quite sure it caused distress. There were other incidents of casual harassment when you saw an opportunity. She must have dreaded her daily routine."

He passed a six month jail sentence suspended for two years. In addition the judge passed a restraining order banning her from contacting Mrs Barber in any way or gesturing to her from a vehicle.

She was also banned from going to the junior school and from going into Ainsdale Road or Matlock Crescent.