I have a 6 yrs old and a 9 year old do parents have to pay to be with the 6 year old?

No. The parents just wear a wristband. They do not have to pay

You do not have to go in with them, they have an observation deck you can relax and watch the kids

Parents can get an "OBSERVER" wrist band for free that allows you to go everywhere with your child, just not jump on trampolines.

Parents can be inside the play area, they just can't actually jump