She's a female. She's considered female by Japanese players. But apparently the English version is trying to pass her off as non binary. And they are taking advantage of the lack of pronouns in the Japanese language from what i heard. This is a few comments i read about it

Yes. Technically in the Japanese version she's never addressed in a gendered way. But in reality nobody really is addressed that way in the game and Japanese itself hardly has gendered addresses, since pronouns don't exist. As another user here posted (Okabe__Rintarou) the entire script of the game only uses 彼女 (girl) four or five times in the entire story so the point is moot. In Japan you just wouldn't address her as "she" or "woman", you'd simply use her name. In addition, other characters use the suffix -chan when speaking to her. "chan" isn't woman exclusive but it's very feminine. You'd only use it for guys when he's a lot younger than you. My Japanese friends obviously recognise her as a girl, while somebody online are a bit puzzled, but the majority still sees her as a woman

Another comment:

The thing is, in Japanese they are super rarely using she/he etc to describe other people. It's evident if you search for 彼女 in game files. It's used only 4 or 5 times in entire script. This is how this language works. If you translate a foreign work that is so linguistically different, you have to take other facts into account, not just one particular dialogue. Following this pattern, Eunie should be nonbinary too because no one calls her "she".You have to take other factors into account, put them together and unambiguously deduce what is what. Yuzuriha(Juniper's Japanese name) is a girl's name. I have never encountered that any character in an anime, manga, Japanese game or TV series is a boy and named Yuzuriha. The suffix chan is mainly used for girls. Possibly as an irony towards a boy if you are close to someone. Yuzuriha uses "watashi." Not even "boku" like other heroines with similar characters. "watashi" is used exclusively by women (and people from abroad) All Japanese posts on pixiv/2chan if they use any gender in relation to her, they call her a girl.The aforementioned one of the major portals on the subject (Dengeki online, owned by Kadokawa) also used kanojo. She even look like a girl. Look at her eyes and compare them with other girls in this game

I also read some other comment about a person telling their Japanese friends about it and apparently the Japanese friends are pretty shocked at the English version. Yet articles and woketards in the West consider it a "fact' that she's non binary and there's been EXTREMELY obnoxious articles on The Gamer insulting anyone that complains about the narrative they try to push and essentially saying "its just a fact that Juniper is non binary and they've already won the future of gaming"