Any laws concerning maturity?

need advice on handling my immature x. She openly stated she’s “being nice” letting me see my daughter. With this kind of attitude you can imagine she skirts the joint custody parts of our divorce decree every chance she gets. At the same time, lawyers advise me to act mature and handle it in court. This is very frustrating since the courts seem not to affect her at all.

I need an effective way to handle these matters, not to mention the stress, that won’t make me go bankrupt.