Talk:Moons/@comment-10390252-20141229175949/@comment-26980087-20150912123637

Best guess I can give you is ,

In Season 3 Episode 8 Apple Family Reunion, Applejack is seen at the last reunion as a toddler who can just talk or our human equivalent, so around 1 1/2 to 2 1/2 years old.

Now if she is a Teen equivalent now in most respects, 100 moons is around 12-14 years possibly as it's been 100 moons since the last reunion.