I'm wondering how the baby monitor and the phone on the upstairs couch fit in.
CW was asked by one of the reporters if he was asleep when Shanann got in. He said "no" but his following words suggested he hadn't wanted to admit that. I can't recall the exact words. The reporter had tried to ask something similar in the immediately preceding question but CW gave a response that had nothing to do with the question that was asked, again wanting to avoid answering that question.
So I do think he was awake waiting for her to get back. His explaining about Shanann's plane being late seemed like it had bothered him that the plane was late, which I don't think it would have been such a big deal to him if he was asleep? And I feel he confirms this by letting it slip out that he wasn't asleep.
So, Shanann comes in, kicks her shoes off, leaves her purse in the kitchen, goes upstairs with the phone. Where would she normally leave the phone at night? Does she normally switch the phone off at night so that they can sleep without any calls/texts bothering them and then turn the phone on in the morning when she's had a shower and had a coffee and more prepared for the blast of calls and texts from her friends and "her people".
Then Shanann goes upstairs to sleep? Was CW downstairs to 'greet' Shanann?
I think she must have gone into one of the girls rooms and seen that her baby wasn't breathing. I wonder if she turned off the phone and dropped it on the couch before entering the child's room?
So she sees one of her daughters isn't breathing, screams for CW to come (because she just knows her baby isn't breathing, she might not realize that it was death by manual strangulation? I don't know how obvious that would be, especially in a dark room where maybe there's only a hall light shining into the child's room so as to not disturb the child by turning on the main light in the child's bedroom? So she screams for CW to come quickly, exits the bedroom and goes for her phone to call 911....And CW attacks Shanann.
Or Shanann put her phone in the bedroom before checking on the first of the girls and had to run into the bedroom to get the phone, CW was in the bedroom pretending to be asleep, and he strangles Shanann there and then, and throws the phone onto the couch (why?) and then hides it behind a cushion while he's doing the quick clean-up before the body dump? But if Shanann had put the phone on the couch before she went into check on the girls, then I find it easier that CW is doing the quick clean-up of the scene, sees the phone on the couch cushion and pushes it between the cushions/seats as a quick fix? So I prefer that scenario, but then I don't understand how the main bedroom sheets come into it if Shanann wasn't murdered on the bed?