Oh, it's so nice to see that you want to translate your game for other languages! (Especially Polish, hehe). I'm really curious how you solve the problem with good pronouns for NB, I'd love to see it. It's time for my language to evolve. I'm waiting for the translation!
Miłego dnia życzę! <3
To be honest, I'm not nearly proficient enough at Polish to be able to judge by myself, so I have to rely on other good-intentioned and knowledgeable people.
Our wonderful volunteer has suggested to me Onu/jenu, so we'll make a small test based on that and test it out. I hope you'll share your feedback when that's out. :)