The court heard how a pregnant woman was punched to the body by another woman during a fight.
Karen Carr, 42, who lives on the High Street, appeared at Grantham magistrates for sentencing, after she changed her initial plea of not guilty to guilty during the trial.
Prosecutor Paul Wood outlined how on July 13 last year Carr went to see the victim at her home in Grantham to ask where a mutual friend of theirs might be, but after exchanging words at the front door they ended up in a fight which was seen by witnesses.
The victim, who was pregnant at the time, was seen curled up in a ball on the ground, while Carr delivered punches to her body.
Mr Wood explained that during the trial the Crown accepted that the complainant had started the fight, but that they judged what Carr did in response as over the top.
Stuart Wild, defending, highlighted that his client had not started the fight and was unaware that the other woman was pregnant until she was told during their altercation, at which point Carr let go and left.
He added that the two women were now quite good friends.
Magistrates described the crime as a ‘nasty offence’ and ordered Carr to pay a fine of £500, prosecution costs of £85 and a victim surcharge of £50.