Thank you for stopping by, I'm glad to hear that you're enjoying the game so far!! :-D Nova's True ending is pretty tricky to get. Early on in the route, she'll ask you if you think Ava's acting out of sorts; if you agree with her, this should open up some more options for you. There's a couple of other key choices later on in the route right after the stargazing event that determine if you'll get the True ending. Let me know if you're still stuck after trying these hints!