You're pretty much going by that based on a theory when in truth there's nothing indicates that she considers herself to be NB, not to mention in the interview the author himself didn't even intend her to be ambiguous when he wrote the story.

https://anitrendz.net/news/2017/10/16/crunchyroll-expo-kinos-journey-author-keiichi-sigsawa-interview/

If you're that desperate for a NB representation, it's better to go for someone who actually fits the bill rather than hijacking a character and the fact that someone cited "anime feminist" site is never a good sign considering their known takes being had like their take on Shield Hero a while ago.