Niche vs. passion

I am working on the Choosing a Niche worksheet and am running into a conflict. The worksheet recommends on focusing on either relationships, health, or wealth. However, I’ve also heard Brooke’s and other coaches’ advice to focus on serving others in a way you are passionate about. I am passionate about helping people in a category that doesn’t fit into relationships, health, or wealth. I could certainly pick something in these categories, but I don’t feel as called to do that. Thoughts?