Elven Aging System
After much meth- uh, maths (which I fail at 100%), it's been decided:
2 Human Years = 1 Elven Year
So for example
Eleina is aged 24 in Elven years, which (multiplied by 2) makes her 48 in human years.
But because elves have a slower aging system than humans, it technically still makes them younger appearance-wise.
Hybrid Aging System
After much more meth- maths and research on animal lifespans (where my brain cells died a little):
Hybrids age faster than elves and humans, and have shorter life expectancies. That is all for now. Numbers will come at a later time because meth.