There is no general legal right to prevent employees from competing with an employer, so the issue is what you agreed to. If you signed any sort of a noncompeition agreement, that agreement is likely to be enforceable (ones which are too long in duration or too broad in terms of what is not permitted are often "blue penciled," or judicially modified by the courts, to more reasonable levels). So if you have signed any noncompetition agreement, your employer may be able to sue you; you should bring the agreement to an employment law attorney to review with you.On the other hand, in the absence of noncompetition agreement (or non-competition clause in some other contract), the employer would seem to have no basis to successfully sue you. The fact that she "said" you could not watch children during work hours is irrelevant in this context, in the absence of an actual agreement; she certainly could have fired you for doing this, but if you're quitting anyway, that will not matter.Note that your boss may try to sue you, even without an agreement--but you should have good grounds to quickly get that suit dismissed.