In the game in Deling City, Ultimecia said She was Condemned for GENERATIONS, that means She already lives for over more than a century or maybe even more.
That info game is the proof that Sorceress' aging is much slower that human.
With that game info it will destroy Square's theory : Sorceress has the same life span like human.
You can forget Square's theory about Sorceress' Life Span because that theory is wrong.
The Truth is Sorceress' Life Span is much SLOWER that Human.