Rick, you talk as if the two of you are not S. Yet, your signature line states that you are. Take away the fact that the two of you still reside under one roof....would you expect her to eat breakfast with you? Would you expect her to share all her information (you said she had been guarded about it), would you think anything of her being rather cool toward you?
If nothing else, she is doing this to remind you of the status of the M. You're expecting her to continue acting like your W......but she's not.
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!