@comeonnow0
Uh, even without Hiroki, imo, they could still probably make use of her, albeit with slightly changed tactics. But one example is when they talked about when her and Hiroki could swap to attacking enemies behind, leaving the rest to fight those in front and removing all but him from her line of fire.
This could still work to an extent with her firing arrows at them while a guard could remain next to/behind her to protect her if a monster survived/dodged her attack and go close enough to attack her.
Obviously without Hiroki it'd need more 'fine tuning', training etc., and there would probably be better strategies, but that's one already mentioned that could explain how she could still be useful in the party even without Hiroki.
Or even like shooting from directly over a guard/tanks shoulder, making it all but impossible that she'd hit them-if they did it right and didn't really leave any room for the arrow to like magically miss so bad it'd hit someone next to/below her with her arrow firing from a position that was already past the guards shoulder/head. Or possibly like riding on one's shoulder, allow the arrows to be fired from a point already 'past' their body. Or like staying in a wearable 'backpack' type thing that the guard/tank could carry on his back, allowing her to pop up, aim over their shoulder and fire off shots while the enemy(ies) were approaching.
And even without that their party is one of the few who understand that she can be useful in the right setup/situation, and be willing to accept her without treating her like the many other dick head groups we've seen.
Oh, and not saying this is 'perfect'/best, or that you don't have a point, I just think there is more possibility of her being usable, even without Hiroki around, than you give credit for.
And I agree with others that it seemed pretty likely that she'd join him with what had been done/said since their meeting, kinda making it a moot point, in a way, though I'll admit it is... a bit of a weak spot in the narrative so far.