I really think IG and AE should both move back to the UK, put the girls first, and co-parent there. Alice has family and friends there and so does IG. The girls would be surrounded by healthier, normal people and get far more support. They can toggle between two households and two extended families. Both parents can work there and I think IG would get work very quickly.
No good will come of them staying here like this in LA. there life together as they knew it is over. AE needs real mental help and treatment and then a solid support system, something she is lacking here. I don't know where BW fits into any of this. I just know the way things are headed, this is not going to end well.