Do I have chance to win the case in the small claims court?

The homeowner called for emergent service for her burst pipes in the winter storm. I was hired as a handyman and she never asked for a plumbing license. But later she threatened me about filing a complaint to the Texas Board of Plumbing Examiners and used it as an excuse to ask for her money back. She disputed her credit card charge in April. That means she got a free service on her 9 burst pipes even though she agreed and signed the credit card charge. After checking the Texas regulation, I found it is illegal for a handyman to perform plumbing jobs. I am wondering if this fact will hurt my chance to win the lawsuit in the small claims court? Will the judgement not be in my favor just because of the plumbing license? Could you please advise? Thank you very much!