>>2185887Several ways to consider that.
How does she look biologically? Around 14 or so. 15 maybe.
What's her experienced age though?
Noone knows. Birth date unknown.
When was Rei I "born"? Some time after Yui's experiment, unknown really, and that was in 2004. So at maximum, Rei is 11 years old, but that's not how it is, is it? She was killed once. So strike off that. Estimates are between 4-6 years of experienced age.
But she's Lilith isn't she? Well that would make her more than several billions years old.
The most practical one is to take her experienced age... she can't remember anything else.
