I think that the best solution is to go back to what english has always done. Mug other languages in dark alleys to go through their pockets for spare grammar. For Instance, German uses a pronoun Sie(pronounced like Zee, sort of... I don't actually know german really well,) Depending on the conjugation of the verb it can either refer to a woman Or formally refer to a person of indeterminate gender. That is something that could be used, then again probably just go with whatever the character decides on. Cause quite frankly, gender pronouns for people who don't fit into normal binary biological definitions creates a lot of discussion. Generally anything that creates this much discussion in the real world will create interesting role play on a table. Politics is just perception writ large.
