You're right.
From age 6 -12 our dominant function develops
From age 12 - 25 our auxiliary function develops
From age 25 - 50 our tertiary function develops
After age 50 our inferior develops
If the theory is right (and I'm not certain it is - I don't think it's nearly so black and white), then for myself the order would be:
Ni
Fe
Ti
Se
My dominant trait from age 6-12 (well, even to this day!!) was that I was quiet.

I don't know that there's any way an outside observer could have pinpointed I was Ni though. Many of my hobbies weren't exclusive to Ni-dominant kids. All you could have pinpointed would have been my introversion. Well, I suppose the J too. So, IxxJ.
Fe? I'm not sure when that developed. I've posted many places that I was a loner, so it's not like I perceived myself as being a feeling type, or really had any outlets where my Fe-ness would shine through. I didn't have many friends at all, mostly due to my quietness and really low self esteem, and just feeling like I was on a different wavelength from everyone else. So there was VERY little extroverted anything as a teenager, just because I was so withdrawn. But as a kid and teenager I was always nice to people(saying 'hi' to people in hallways even though I knew we weren't friends, but I wanted to be their friend) and wanting to please others and be accepted by others, so in that sense I suppose I was exercising Fe. And it *never* occurred to me to stand my ground and be a more defiant child -- it never crossed my mind that I could just refuse to do things, scream at my parents, lock myself in my room, etc. I'd always ultimately want to please my parents, and didn't want anyone's disapproval. I rarely talked back, and wasn't inquisitive in the sense of questioning everything about life -- I might have questioned internally, but I didn't engage my parents with my questions very often. I was pretty much a child that didn't cause my parents any problems, and was a good girl and I suppose an overachiever.

(although they may have worried about this and my quietness, for all I know)
Ti? I don't know, I think I had that as a teenager too, because of schoolwork and testing. And I might have latched onto Ti earlier simply because I was a loner and didn't know how to socialize. Incidentally, since I was good at intellectual stuff, I viewed myself as more of a thinker. I was always good at understanding concepts, and classwork was usually effortless for me. Then in my early to mid 20's I became rather consumed with a Ti perspective (this is when I'd always test out as INTJ).
Se pulled me out of the Ti perspective, and it now trumps Ti. Ti tires me, and I don't value it as much anymore. It's not that I can't be incredibly analytical and stick to the logic and cold hard data, because I can, and I have in the past, I just don't place a whole lot of importance on a strictly Ti approach these days. But Se...perhaps I've had an element of it too for a long time, because of my love of being out in nature and just looking at the world around me. Se is probably also the 'rush' I feel when I'm traveling. And both of those things are incredibly important to me and I'm moving much more towards seeking experiences in my life. So I guess I hit my inferior trait 25 years early.
Oh, and I'm sorry Alcearos, I totally derailed your thread. I didn't answer any of your questions, I was only commenting off of INTJMom's post.....But I was an IxxJ child....