First of all I'm going to apologise for pronoun and term mistakes. I don't mean to offend but I have no idea if I'm using them right so feel free to educate me if I've made a mistake.

So on Monday my sister-in-law posted to Facebook introducing us all to her teenage son who until then has been my niece and I have questions.

Question 1: Is there a correct way to say "My niece is now my nephew"? Also is this a "coming out", a "transition" or is there another word for it?

Question 2: If I'm referring to them but in the past like commenting on a dress they wore 2 years ago, what are the correct pronouns? I'm thinking it's he/him but I'm not totally confident.

Question 3: Is some amount of identity experimentation normal before this sort of announcement? My nephew spent all of winter break in a tiny skirt, tiny top, long purple wig and cat ears. While it sucks to admit it my initial reaction to the announcement on Monday was to say that anyone who spent a few weeks recently dressed like that doesn't suddenly decide they're male and so they weren't totally serious about it. However, the more I thojgh about it the more I've wondered if it was just them trying to express themselves and find their comfortable place.

I feel I should also point out. This nephew is technically my step-brother's wife's child from a previous relationship. I didn't meet them until a couple of years ago and have only seen the in person / spoken to them 3 times in total. So I know I haven't seen the whole story and the chances of me interacting with them in any major way in the next year is slim.