Can a niche be too niche?

Hi there,

On my business, I know my niche pretty well. To reach it and talk to it, I’m working on Facebook ads with a good targeting strategy. What I can’t figure out yet is how to really select interest that matters to them.

Let me explain. I know who my ideal customers read, who they love and get inspired by and so on.
So, normally I could target only people who have “the right interests” to see my ads.
What I can’t figure out yet: I’m French and work with the French speaking markets.
When I type the name of somebody super known and loved for my targeting, Facebook doesn’t allow it as a criteria. It seems to be the same for many French pages as they are too small compared to pages of English speaking markets.

I am sure there’s a way around it though I’m still working on it. What are your thoughts?
Thanks a lot.