system
A chat on subreddit /r/NoStupidQuestions
human
"She/they" means she answers to she/her pronouns AND they/them pronouns

It's good policy to just ask someone's pronouns when you first meet them, but if you're worried that'll come off coddly and annoying (as it sometimes can), just make a best guess off their appearance/demeanor and they'll correct you
gpt
I’d say just make an assumption based on how they present and if you get corrected, respect their wishes.