Yes, it is possible for her to sue you. She would have to show that agents of your gym knew or should have known about the hazard and she did not know about the hazard.
If your business has an insurance policy, I strongly recommend that you make your carrier aware of the incident.
Please feel free to contact me if you would like to discuss in more detail.
Answered on Feb 11th, 2013 at 11:14 AM