It makes me a little nervous when the WW starts moving things so fast, b/c it is a process that one doesn't get through in just a few days. Like I said, women like to feel that the deal has been sealed in relationship matters, so she may see her moving back into the house as the seal. We have seen a few WW's do this, but most are hesitant about jumping back.....especially those who have not faced many consequences. Although she has said and done what she needs to do, I agree that you need to stay on your toes. I think it would be a big mistake to let her move home this quickly. In fact, I hated to hear that you are letting her sleep over. Seems a little fast right after OM, but maybe that's just me.
The withdrawal will be more than just her grieving the A. She will crave it, too. Right now, she's angry at OM, but I think it will pass, eventually, and she will have to deal with actually wanting to make contact with him. If she can overcome that temptation (many times), then she'll have a chance at beating it. Of course, the depression is another obstacle.
I know I hammer about the amount time it takes, but most LBS's I have read about, are so anxious to get the MR back on track that it pushes things too fast. In this case, however, it sounds as if she's the one pushing.
You seem much more level-headed now than you did just a couple of weeks ago. I hope you will stay smart. There is hope here. There is a real possibility for a new MR.
It is not about what you feel should work in your M. It is about doing the work that gets the right results. Do what works!