@confusis2222,
Roger is correct. The case is "closed" in CA from the standpoint of the state's enforcement of the support order. You are still ordered to pay child support, and you will owe the currently ordered (from CA) amount for each month that goes by. Your child support arrearage is increasing each month.
She can "re-open" a case in PA, for purposes of enforcing the current order, and she can register the order there for that purpose, or in the state you are living in. If she wants to modify the existing order, she will likely need to file in whatever state you are living in ... or if you want to modify the existing order, you will need to file in PA where she lives -- per the Uniform Interstate Family Support Act (UIFSA) .