Everything you say could also be attributed to a serious health issue, especially gastrointestinal (bloating, insomnia, mouthwash would take away the taste of bile, poor self-care, medication could cause confusion). The fact that she puts stuff away in the bathroom and not some other room suggests that too. Generally alcoholics who live alone don't keep booze in the bathroom. You haven't seen any alcohol or smelled it judging by your post.

Regardless of what it is, it affects her job performance, and you two should discuss it.