By using various elixirs I've been able to bring my family to the point where my founder MIGHT be able to make her first batch of Ambrosia while still an adult. Does she have to wait till she's an elder or if she finishes the last thing she needs, (LTW completion), can she eat the ambrosia sooner? I know the rules say:
"Start with one Sim. Only by accomplishing key tasks is your Founder granted the power of immortality upon reaching Elder status."
but was wondering how hard and fast this is. I doubt the heirs will have as good a chance of completing everything before they are elders but my founder had so much help getting everything done, including her quickly learning alchemy and getting the elixirs, that there is a chance she might actually complete everything before then. Right now it's at the rinse and repeat stage of gameplay.