Three women have been found guilty of beating up a relative after a family feud erupted at a school car boot sale.

Linda Smith, 46, her daughter Eliza Smith, 20, both of Woodmansterne Road, attacked their cousin Louise Green at the car boot sale at St Philomena’s School in Carshalton in April 2009.

Rosie Smith, 19, of The Pastures, Banstead, who is also Linda’s niece, was found guilty of the same offence.

All three women were also found guilty of another assault on Mrs Green’s husband Terry and one other of threatening behaviour towards the Greens.

Rosie’s mother Minty Smith, 46, was cleared of all three charges.

During the trial, the jury were told that Mrs Green’s husband, Terry, had approached the four defendants at the car boot sale after posters announcing his wife’s breast cancer were circulated around Carshalton.

After heated words were exchanged a fight ensued between the Greens and the four Smith women, leaving Minty with two black eyes and Mrs Green with a stab wound to her stomach.

The mother-of-three, who gave evidence behind a screen, initially told the court: “It couldn’t have been me who did Minty’s nose. I don’t think I can hit that hard. I’m a lady.

“I saw Minty with a knife and she was going for my husband.”

However she later changed her tune admitting she had punched Minty as opposed to her husband.

The court were also told that Mr Green had spent six months in custody in 2008 after “wild and malicious” allegations were relayed to police by the Smith family.

It was after this spell in custody, the court heard, that the alleged poster campaign began against Mrs Green.

It was alleged that crudely edited photographs of the mother-of-three with a breast cut out were posted in the surrounding area.

The three Smiths, who all appeared at Croydon Crown on Thursday (December 17), were asked to return to court on January 24 for sentencing.