Saw a few posts about gender neutral pronouns in Irish so I thought I'd talk about it a bit.
So like others have said, there's no native gender neutral pronoun, traditionally in Irish if you don't know someone's gender you'd call them duine (person) which is grammatically masculine, and then use masculine pronouns to refer to that.
But of course there's lots of non-binary people who wouldn't really want to use masculine pronouns so let's talk about alternatives a bit.
Siad is originally a plural pronoun in Irish meaning "they" (pl.), but is the most commonly used option nowadays for non-binary people. It is a direct calque from English, but as far as calques go it's a pretty useful one.
Neopronouns are pretty tough in Irish, harder even than in English where still they have pretty low adoption rates. This is because pronouns in Irish come with a lot of grammatical baggage. It's not enough to say "subject / object / possessive"
A pronoun in Irish needs to have subject, object, possessive, and a prepositional form for every preposition.
Like for brevity we often write pronouns as like sí/í. But in reality what we have is:
Subject: sí, object: í, possessive: a (h-prefixes, no lenition), ag: aici, ar: uirthi, as: aisti, le: léi...
So to create a neopronoun you have to both document all of these forms, and then get people to adopt them (which is hard, because there's more to adopt).
Also for the possessive form it's hard because the third person possessive is always a, it's just that masculine lenites, feminine h-prefixes and plural eclipses. If you try to add a different a, it will have to have the same mutation pattern as one of them, at least in many situations.
One possible solution to this is to use a neo pronoun but use the grammatical forms of siad, so like tá siú ag obair ag labhairt leo féin (they are talking to themself). But at that point we are still calquing from the english.
ea exists in the language in certain situations as a neuter reference, historically it existed more, but if you tried to use it now you would have similar difficulties to the neo pronouns, you'd need prepositional forms.
Also, é gets reduced a lot in speech especially in Conamara, to the point where it would sound very similar to ea if you were trying to say things like Is dochtúir ea for "They're a doctor" it would sound a lot like Is dochtúir é "He is a doctor".
Because of all that, I think generally the most flexible option is to use siad, even though it is a calque of English. But for those who would like neopronouns, now you're prepared for the large table that comes with it!
If you want something that's a little bit neo a little bit traditional you could consider adapting dar, the ending of the 3rd person plural past in words like bhíodar (they were). This ending has become a pronoun in some limited contexts (still for the plural, but stuff like tá dar - they are) but if you wanted to use it as a singular pronoun with the grammatical forms of siad, that could also be an interesting option.
