sura

Since the beginning Leez knew that Yuta was "different", but he didn't want her to know/tell her for fear that she would distance herself. And so Leez pretended to not know anything, acting as the clueless bird brain, waiting to gain Yuta's trust so that he could tell her himself. Which he didn't (in season 3 was it? I don't remember when The Company stopped translating, but that's when I dropped it because A;LGHAOEUICABI;UEW THE TREATMENT OF LEEZ AND HER OWN DFL;SAKFHIEBVAI) *sigh* There was that one thing where Yuta ate her and she was like half-dead, but after recovering, she pretended that she had no memory of being eaten alive... There was also that one thing where Yuta was eating something in the cave under water and Leez happens upon it... It's implied that Leez knew it was Yuta who was doing the *crunch crunch* on the other sura's still alive body and all

As said, she actually found out that he is a sura long ago, but she played dumb hoping that he'll trust her enough to tell her himself one day. So, the question of whether her behavior changes as a result isn't really relevant (since she already knew). Yuta does eventually 'reveal' the fact to her by transforming in front of her to protect her though. She tells him then that to her, he's still the same Yuta.

Rather, her attitude towards him does change after he develops, but that's more due to the fact that he's no longer a cute little boy that she can hug all the time. Plus the fact that Yuta starts emitting an alarming amount of pheromones. She tries to act normally around him though.