I have a project I have been working on for many years. It is quite personal and is intended for a small audience.
In the story, the protagonist is trying to find/help another character, who for most of the story is not named. The other characters know who this mystery person is, know the relationship between her and the protagonist, and will often refer to her by generic references or titles.
I am worried that not naming her, or referring to her by name would be frustrating.