Divorced and moving out.....still hopeful

[NewB3]

Tonight she calls. She asks if I am busy. I tell her I am eating dinner. She then tells me that S4 is giving her a really tough time. She put her phone on speaker and asks S4 if he wants to talk to daddy. He says hi. Tells me he does not like his mommy. He says he will kick her and punch her and going to throw food at her. I tell him we do not do things like that and that he needs to love mommy and be nice. I hear her tell him not to throw food. She then says to call her tomorrow about dropping him off at my home. She is in tears to the point she can almost not speak. I tell her I am sorry she is having a tough time and hoped it got better. She said thank you for saying that and said she will talk to me tomorrow.

He is really raking her over the coals about this split up family. I feel for her, but cannot help but think she knows this was all a mistake at this point. Her child is suffering, lashing out, asking for his family back. He is only 4. Makes me angry and sad. I have given her the space she asked for. I still never call, email, text, etc. she has to call me 99% of the time.

Thoughts on this? Recommendation on how I should approach her, if at all?