"I told D11 that I'd love to have her and D8, but I don't think STBXW would ever recover if that happened. She needs them."
You just put a huge ugly responsibility on your girls. If you are making decisions about their lives based on what is best for STBX's mental health, that is unfair to them. Nor should they expected to be responsible for keeping STBX happy or stable. Please be very careful with your words.
Have you considered having just a C session on your own to talk about how to keep from putting your kids in the middle of things and how to avoid burdening them with STBX's care and upkeep, as well as avoiding codependency traps?
Your involvement in the stroller business is bit of a mess. You are getting divorced. Stop trying to manage STBX's physical and mental health. It isn't appropriate. The codependency here is sick and thick. It could help you a lot to get involved with a codependents group for your own sake.
