Out of total boredom, I've decided to try out modding, and of course I started out with one of the hardest projects I could come up with, adding a new life stage. I honestly just want to know whether or not it's even possible. My plan is to make them the same height as kids, but give them a body preset to make them look more mature, along with new interactions for middle school and stuff. Just playing around with the files I have gotten kids, to age up into kids, though it happen every time, and i have no idea why. I feel like it is possible, though really hard, but I'd like to get some other opinions, am I wasting my time?

It isn't possible to add a new life stage.

After continuing to mess with the files, I still think it would be possible, though not for me. My new thought is instead of adding a new life stage simply make it so that kids go through puberty and go to middle school after they hit a certain age. Essentially dividing up the child life stage in half, without actually dividing it.

sounds so awesome the sims 4 team should hire modders since they don't do anything right xD