For the simple theft charge, the court usually order the defendant to pay fine instead of imprisonment. After conviction, the immigration will not issue new working visa to the helper for about 3 years. But if the existing employer is willing to keep the helper, she can work until the end of the contract.
$200 is cash bail. She paid so that she can be released and wait for the case to be brought up to court. I have heard that some employers terminated the helper immidiately when she was formally charged by police. You'd better enquire the labour department first. If I were you, I won't let her stay until March to avoid trouble.