Welcome Box Turtle: Sorry to hear about your sister. The situation with my sister, and reading "Stop Walking on Eggshells" brought me here as well. I'm glad you have such a supportive spouse. I'm guessing he didn't say, "I told you so".
Setting
BOUNDARIES ,
NOT INVALIDATING (VALIDATING), and using certain
COMMUNICATION SKILLS can make things better.
Are you able to share some examples of your sister's behavior? With more specifics, we might be able to suggest some specific lessons/skills to help you. How long have you been no contact (NC) with your sister? Was there a particular event that made you decide to stop contact?
We look forward to hearing more of your story.