If someone is 'spared jail' it means they have avoided being sent to prison. So the woman in your example committed a criminal offence, but the judge decided not to send her to prison for it.

This is typical 'journalese', used in news reports and headlines. It means that the woman has doesn't have to go to jail. Most probably, she was arrested and appeared in court and found guilty. The judge or magistrate could have sent her to prison, but decided not to. She probably has to pay a fine instead.