With a hug? She gave her a hug in a calm moment after writing her a love song and she doesn’t know?
People hug their friends with no romantic feelings involved at all quite regularly, yes. Or in spite of whatever feelings they may have but have not opened up about - particularly during highly emotional moments.
Given prior context of behavior that Koga has displayed, she's a bit dense and evidently views herself with a lot of pessimism - so at BEST, she'd think her own feelings are likely one-sided
(and this is also assuming Koga's even truly rectified that this is romantic love - once again, our girl is a neutron star when it comes to this).
I'm not saying
"and they were the best of friends, and that's it" a la historians and Toei, BUT this moment is very clearly about this next step in self-acceptance for Koga, and the feelings of gratitude she has towards Aya for confirming she has someone that will stick with her even outside of her perceived family. In otherwords, Koga has been too preoccupied with her own emotions to fully recognize those of another - which is completely normal.
I'll ALSO add, that it's not outside of the realm of possibility that next chapter will present us with stronger proof of Koga's feelings and awareness of things during that time off-screen. In fact, that could very well be the perfect time to put those pieces together; But that moment was not
this moment. That's all I'm saying.