that's where you're wrong, it's implied a lot by the author that Sasha like Hyce from the start, it's literally the reason why she's always jealous when other girl got close to him or when someone ask her about hyce she got flustered, heck, she even think of hyce a lot
even from Reynold PoV from one of the chapter, he even said it himself he knew that Sasha likes Hyce, but she just didn't notice it which is also why he said in said chapter he had a shot (it's also the reason why Reynold doesn't want Sasha get close to Hyce, he doesn't her to notice it)
when Eclipse and co. appeared, it's already at the point she finally understood her own feeling and the other heroine also made her realize clearly as well, when other heroine said they want to marry Hyce, she noticed her jealousy is actually her liking Hyce all this time
as i said, author written Sasha to be clumsy and naive, also stubborn in a way, and dense, Hyce actually realized a lot of other heroine liking him way earlier than Sasha even noticing that Piazolla actually like her not as a friend, Hyce just ignore it
Hyce only didn't notice Sasha feeling early on because his hatred is bigger than his other feeling for Sasha, he immediately notice his own feeling and sasha's when they got closer again, but just refused to accept it
Oh she loves him and feels jealous but at the same time she doesn't reject Reynolds and she also said that she loves him and admires him whether a little or a lot and she also said that she was happy when Reynolds confessed his love to her and she didn't reject him I don't see her as a heroine in terms of personality maybe she is a heroine in terms of appearance and strength but not in terms of personality. Even when she said that she rejected Reynolds she kept praising him until Hayes stopped her man this is disgusting if the girl you love said that she admires another man even if she loves you 100/90 and loves him 100/10 would you still love her. She also loves the man who kept talking badly about you behind your back, insulting you all the time, and trying to steal her from you. Will you continue to love her?