Welcome argila and well done for passing!
I'd say it'e each to their own. I went pillion with Mr Lady Clara only a couple of months after he passed as he felt comfortable and confident enough. It was fine and we had no mishaps.
I passed 8 months ago and haven't taken anyone pillion yet. I would probably feel ready now but am in no rush. I'd say if you're still riding your 125 and feel confident on it there's no need to wait for a year. Just do what you did when you were learning (or what I did anyway), go to a car park or industrial estate with your Mrs following in the car. Have a go with her on and see how it feels before you go on the road.
Good luck.