You had a rough day...Really rough. This is what my coach would say: -Your reaction to the FB picture is natural, and even though it might not be DB, it's what you needed to do, so don't feel that you messed up or anything of that sort. -You did the right thing by expressing your feelings about her behavior and by offering your support. Just make sure you don't end up making the appointments with the IC and asking her how it went. Remember, let her do stuff. Let her make mistakes. Her behavior is so similar to my H's in many ways. I think both you and I are people who take care of others and take charge of problems right away. My H said once that I was "too nice." He said that was a problem. I think that he was right. I became a doormat. Be loving and supporting, but stand up for yourself.
What do I think? It's just an opinion, and only you know all the details of your sitch, but if she continues this behavior (I have a feeling it'll stop) it might be best for her to move out (or you, if you can't make her move out) so you can actually spend some time apart. The in-house separation scenario sounds really stressful and confusing to me. I am aware of the financial constraints, and the logistics of the kids' schedules, but I'm sure you can make it work out. This might be the awakening that she needs...Just my thoughts.
