One of my fellow rescue volunteers has 1 cat (of her own) that lives its entire life in one bedroom. ALL her other cats HATE this cat and attack her. I never asked this lady point blank why she doesn't just find a home for her, but obviously she loves this cat and feels that this life is meant to be.
another example.
Our shelter building is loaded with cats that spend much of their life in 1 room. Many are unadoptable and will live there forever.

I think that if you feel you can spare her a room of her own then keep her, or at least keep her until another situation allows her to find a different home.