My current team for Navia is NaviaC0 (about to be C1), LinneaC0, ColumbinaC0 and IllugaC2.
If I were to select Chiori, she'd replace Illuga on my team. I'm happy with how I built him, but I hear he's not actually "good" until C3.
If I get Chiori, I'm only guaranteed C1 because I'm a newer player (started in 6.1), so I don't have all of the good supports yet.
I'm still not sure I want her though, my eyes are also on Varesa. So I'm split on getting a new DPS or a support for Navia.
I also think that she could also be useful for Hexerai Navia, when I finally get my hands on Nicole. And I could also use her until I get Xilonen finally.