A 24-year-old woman who assaulted her eight months pregnant sister has been told she should have grown out of such behaviour.

Sarah Reed was given the warning by a judge after she admitted slapping her sibling.

And he told her: “If you are before the court for this sort of thing again a much more serious penalty will be imposed.”

Tessa Hingston, prosecuting, told Swindon Crown Court there had been problems between the sisters for some time before the incident.

On the evening of December 6 she said they were on some parkland where Reed had been talking to a man she had met.

She said the siblings argued about whether she should go home and her sister, Nicola, seemed to be thinking she was acting in Reed’s best interests.

The pair continued to argue and Reed slapped her sister in the face.

She then hit Nicola’s boyfriend Scott Sommerville when he tried to separate them.

Miss Hingston said there had been some suggestion that Reed had struck her sister, who was 36 weeks pregnant, in the stomach but she had denied doing that.

She said that a medical check showed there had been no problems caused to the unborn child as a result of the incident and the basis of plea was accepted.

Reed, of Southwick Avenue, Penhill, pleaded guilty to two counts of common assault.

The court was told that she had cautions from 2005 and 2007 for similar assaults which were also on her sister.

Mike Pulsford, defending, said “It’s a sad situation this,” adding that it had caused divisions in the family.

He said his client thought her mobile phone had been thrown away and lost her temper, slapping her sister.

“Temper control is an issue and occasional binge drinking is also an issue,” he said.

Judge Douglas Field imposed a one-year community order with a conflict resolution and an alcohol education course.

He told her “You are 24 now and you should have grown out of this sort of behaviour towards your sister.

“The worrying aspect is you have had two cautions for similar behaviour, she being the victim on each occasion, and she was pregnant when this happened, and thankfully that was unaffected by this assault.”