At the moment, she is very selfish. So she just uses Celica as a frame. And a full friendship is not really possible here. Maybe the core of the problem is what was done to her in the Order of Mages.
For sure but I feel when that about now or the next step seeing how she still cooperate well when you ask her stuff then the idea to just make suggestions as to a way to be together wouldn't be to far out
Mostly I also think game wise this would be nice as well cause while you can ask her to get you go its tedious to go through every time so have an agreement ahead based on your bond being deeper would be nice both to show her progress but also to make it more useful to use her