My step daughter is being stalked by her soon to be ex-husband, need some info

Sounds like these 30 year old grown ups need to grow up.

They need to figure out how to raise their child the best way they can. They bonded in recovery at AA and have some tools and desire to be healthy.

They need mediators to help communicate how they will come parent. They won't benefit from tactics that undermine each other. The stalking needs to be called out and agreed to end.

Enlist sponsors through their mutual AA to help. Don't escalate this by one upping in dirty tactics. This man is the child's father and deserves to be a part of his kids live. He is scared and chosing fear, give him space to chose better. Give him an out.

Tell step daughter it's time to grow up. Get her life together before getting in to another romance. I'm betting she has a new man already and that's what this is about.