You don’t have to be a dedicated yogi or spiritual. You need to be ready for change and curious. As the plan includes breath work and other embodiment tools you should feel physically healthy. When pregnant you shouldn’t hold your breath in the exercises which is explained at the appropriate point in the workbook.

No, you only need a way to document your journey. I suggest a phone or camera and a notebook or your regular journal

No, you can take the 12 nights whenever you want and not only during winter. It might be even nice to do it bi-annually when seasons or life circumstances change