So, Kumino is still unsure whether she wants to change and take music as seriously as she used to, and that's keeping her from making up with Reina and sorting things out? Because if it turns out she won't bother to invest her everything in music again, they would just inevitably clash again. Yet at the same time some part of her does yearn to get closer to Reina and become her friend. Considering how Kumiko is quite good and at the time being is practicing and performing sufficiently, I don't think there's anything concrete keeping them apart, especially since Reina clearly doesn't hate her and in one way or another even forgave her, if there was anything to forgive in the first place (indicating it's just Kumiko's personality quirk that caused the conflict).

Dunno. It's much easier between guys, right?