WHAT? 9,002 YEARS?
There's no way that can't be right, that makes her older than... maybe the Roman Empire, I guess.

Ephitets doesn't have to be taken literally.
It simply means a con rabbit who has lived for a very long time.

Like the number 7 or 8 is used to say something many.
Or 101 could mean beyond perfection because it's over the full 100.

Still… East Asian’s way of screwing the kanji into totally different meaning is amazing.
Turning 白 (white) into 99 (百 100 - 一 1) is easier to understand.
But deconstructing 麦 (wheat) into kanji for 久 9, 千 1000 and 二 2…

There's also the fact that time moves differently at Eientei anyway(This is regardless of how long Tewi lived there). Suppose it depends on how you look at it, but if I were in a time sphere and moved 1000 years inside of it while the outside world only moved 1 year, I would consider myself 1000 years older.

Tewi is the White Hare of Inaba, which came from the approximation of Kojiki's first compiled 'date', going through the creation of Japan. Calling her age 'myriad of years' is not an exaggeration, I guess.