Kudos for stepping up while she tends to her added responsibilities at home! And good for you for thinking of the finer details, like insurance coverage for your group.
Elly thinks you should first give your parent group’s insurance policy contract a quick review. There likely may be wording that stipulates whether any and all of your volunteers and officers are protected or whether only individuals specified on the document are covered. If the policy requires that the names of each parent group member be listed on the policy, then, yes, you’ll need to contact your insurance company and have those changes reflected on your insurance documents.
Good luck with that carnival. Elly would say "break a leg," but, well, she thinks that you’ll probably need two good limbs for all that running around you’ll be doing.