An antisocial behaviour mediator has been ordered to attend diversity awareness classes after being convicted of assaulting three people at her children’s primary school.

Diane Marquis, of Songhurst Close, Croydon, screamed at a same sex couple they were “dirty f****** lesbians”, spat in the face of one and stuck her finger up the nose of their friend outside West Thornton Academy School.

Croydon Magistrates’ Court heard the 51-year-old also told a teaching assistant: “I will kill everyone. I will go to prison for my children. I will protect my children.”

The mum-of-three’s attack, which was witnessed by up to 25 children aged between five and 11, followed a row about her children and the other women’s children.

Marquis denied, but was convicted of, assaulting Isobel Hodson, who is in a civil partnership with Stephanie Richards, and assaulting Debbie Cooplestone, another parent who became involved in the row on June 20, last year.

She was also found guilty of three counts of threatening behaviour towards the couple and the headteacher Jo Simmonds, and of harassing the couple at the school between June 13 and 20, by using homophobic language.

Eka Kalunta-Ike, prosecuting, said: “Ms Richards has described four incidents where she has been verbally abused by the defendant, who has used homophobic language in the hearing of other children, including hers.

“When Ms Richards collected her children from the school on June 13, the defendant shouted at one of her children and the child started to cry.

“The defendant then swore at Ms Richards, referring to her as a ‘f****** lesbian’.”

Miss Kalunta-Ike said a week later Marquis again arrived at the school in an aggressive mood.

She said: “She abused the couple, calling them; ‘Dirty f****** lesbians’.

“Parent Debbie Cooplestone, challenged her about her behaviour and was assaulted.

She said: “The assault involved the defendant sticking her right index finger in her right nostril, causing her discomfort.”

The court heard Marquis was unhappy at the way the school handled a fight between her son and the same-sex couple’s daughter, suggesting there was an organised conspiracy against her.

She told the court: “Their son has been to my house for tea. We have each other’s phone numbers and I have no issue with their sexuality. I approached her with respect. I was not angry.”

As well as the diversity awareness classes, Marquis was made the subject of a 12-month community ordered, ordered to carry out 200 hours community service and pay each assault victim £100 compensation.