My question really falls within consent to participate. My sister does not want her daughter to participate in gymnastics. Her ex-husband (well more her ex-mother-in-law) wants this little girl to participate. Her ex took their daughter to a gym and signed her up. With my daughter participating I know the drill of consent forms. But, in the situation of joint-legal and physical custody, can one parent sign a child up for gymnastics with the other parent against it My sister is also the insurance holder for her daughter. Can her ex really sign something saying the girls insurance will pay if she is injuried when it is not his insurance? The owner of the gym said it does not matter to her the custody of the child just as long as a parent signs. She said she does not need both parents signatures if the parents are separated. How accurate is the owner with the liability aspects of this?Thank you for any help.