A trans parent would likely still want to be called “Mom” or “Dad”, I assume. At least that’s the case with the few trans parents I know.
Parents don’t usually use “daughter” or “son” as pronouns, so I don’t think it would come up with non-binary children.
Do children of non-binary parents call their parents by their first name? It seems unlikely that they say “Parent, may I please have more screen time?”.
Tangential, but my wife is nonbinary and I still call them my wife. They’re okay with it. And I don’t mean to be lewd, but in bed they like to be called Daddy instead of Mommy. My point is that it’s probably a case by case thing without a universal and some nonbinary folks don’t mind some gendered terms. It might even be context based.
Interesting! Thank you for sharing.