I have a similar setting that is still considered, 'normal', but gives adults and elders a few 'extra' days.
I actually feel that a young adult should be younger than 30, @ 21-25, and cover about 10 years, and adult should start @ 35-40, but I didn't want to shorten any of the younger age groups, so this is what I came up with.
Age group-starting age # of days in each age group
Baby-0 3 days
Toddler-3 6 days
Child-9 7 days
Teen-16 14 days
Young Adult-30 21 days
Adult-51 28 days
Elder- 79 21 days
Lifespan = 100 days
Even so, Sims can surprise you!
In my Town Jump game, my 1st gen heir, Rae Frio lived to see 4 towns and reached the ripe old age of 128, only having that 100 day lifespan!
And in my Farmacy game, my 1st gen heir, Summer Swanson, lived to be 135, only just recently out-lived by her son-in-law, Leonard Diwan Kindle Swanson, who met grim at 136 days old!
Though maybe they were sneaking Lifefruit when I wasn't looking or cooking it up in pancakes!
As a caution to any other unknowing players out there, wishing for long-life from a Genie in the lamp, doesn't just give the sim wishing for it a few extra days.
It actually doubles their remaining lifespan days for EACH age group, not just for themselves but every generation after that, starting at birth!
That happened in my Town Jump game when JoAnna Drudge Frio made that wish so she'd have more time with her fairy husband, Crewe!
It did help give all her progeny, right up to the current 12th gen, longer life, but not just the humans the fairies, too, so they were almost immortal!
Which meant not only having to age up all my babies, toddlers, children, and teens, @ halfway through their age spans, to actually get to move to the next towns,
but leaving my fairy heirs and spouses behind in their 3rd towns from that time forward, or else I was never going to get through all 18 towns waiting for fairies to meet Grim!
