Customer complaint 2 weeks later what to do.

Ok so I groomed this person’s dog 2 weeks ago and just had the daughter call and complain that I had cut the dog in the face. Which i know I hadn’t. I have before and after of the groom. The daughter claimed because I used a bandanna on the dog that I was trying to cover something up the cut was on the front of the face. Also she claimed I was taking advantage of the elderly. I’m forward with my clients and if something does happen I of course offer to pay for them to go to their vet. Worth it keeping as a client? The client is awesome but I don’t know if it’s worth it to have the risk of the daughter bash me online. Which has already happened on her personal page.