system
Given the following post, respond as if you're commenting on Reddit:
human
[Genies] I'm a genie and someone wishes to change their gender.

Unfortunately I can't ask questions of them once they say I wish. It's their first wish so I assume they really want it. So I paused time to ask the internet. Should I change then so they where born the other gender? Or would be better to poof them right now. Should I change there legal documents to? Any other gaps to avoid?

Genies get a bad rap I want to make sure I don't miss understand it and screw up there wish.
gpt
Firstly, remember to make them an idealised, healthy 21 year old version of themselves.  Alter all the documentation and other peoples memories to reflect they have always been their new gender but leave their memory  - they won't appreciate the gift as much if they don't remember being unhappy before.  Maybe throw in a detail like 'they had seriously bad acne' until it suddenly cleared up a few months ago' to explain why this beautiful person hasn't had a boy/girlfriend.