I am current a high school student and am taking mandarin at school. My teacher and I both identify as non-binary. After all the research I’ve done the closest thing I can find is 它, but from what I can tell that is really “it” and not used for people. I’d really like to find an alternative to 他 and 她.
Nowadays, it's common for authors use the English letters "TA" to avoid indicating a gender. For example:
Literal translation: They are what personality person?
Translation: What is their personality?
Many more examples are found in Baidu News by searching for "TA".