esmeiolanthe

I don't know how long it takes either, but I believe there are certain life milestones that do it. You don't want to avoid hitting those, as I think they often give a lot of aspiration, but I'm sure it takes longer than the transition from Toddler to Child, which I my personal best. Like I say, if you can manage that, you can declare yourself /a/ Simming Goddess -- and that ain't bad. :)

If you decide to try, best of luck! :D