I would like to suggest something for you to try. You may have to use your imagination or even pretend playing a part. If this woman who shares your house was not your wife, how would you act in these situations you've mentioned? How would you treat her? What would your attitude be? For an example, when she starts off to bed, you would not kiss her forehead, right? Not if she was just some person who was there for room & board.
Just for the sake of using your brain for something other than fretting, try this exercise. Of course, you don't say anything about this to anyone, it's just to see if it helps you deal with the current situation. Think of her as someone who is there for room & board, but you have totally no person interest in her. Her personal business is not your business, and vice versa. You don't ask her questions about her activities, when she plans to be home, etc. You don't "try to get her" to do anything.
When the two of you happen to be home at the same time, you are polite, kind, and mannerly. But you do not try to get closer to her. It is strictly a business arrangement. Get the picture?
Try it out and see how differently you feel and act dealing with her. Even if only one evening, just in your own mind....pretend. (Of course, she is not to know what you're doing.) Then tell me about the day or evening.
I hope this exercise will show you something better than perhaps I can explain in words.
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!