回复：法律咨询:雇主拒付工资怎么办

Of course it is illegal for them to hire you who does not have work authorization.

They are different issues, you work illegally and they refused to compensate you. You are not permitted to work. But it does not mean that you are not entitled to be paid for what you have done. They have a legal duty to pay. Although the employment contract, whether oral or written, may be deemed void because you are not authorized to work in the US, what you have done is entirely lawful-providing babysitting service and you should be compensated fairly.

Fight them. They violated the law too because they knew you did not have work authorization.