Why didn't Wesley Mathews wake his nurse wife as Sherin Mathews choked to death?

https://www.washingtonpost.com/news/post-nation/wp/2017/10/24/father-of-missing-3-year-old-now-says-he-watched-her-choke-on-milk-and-die-affidavit-states/?utm_term=.340c5613c14b