Why is Mai "Ancient"?

[g33k]

Elsethread, I remarked: 

...  it's interesting that (alone amongst all the Senior Council, all of whom are extraordinarily long-lived) Mai bears the epithet, "Ancient."  It implies (rather strongly) that she is unusual even amongst wizards ...

We know that McCoy & Langtry fought one another in the 1800's.

We know that Rashid is (at least) 1000 years old (though it's possible his time in the deeps of the nevernever has seen him gain centuries of nominal age, just from the magical time-dilation).

But it is Mai who is "Ancient."

Why is that?
How old is she, really?

And, most importantly:  what will happen when Jim picks up Chekhov's epithet and pulls the trigger?

[Mira]

  She could be Rashid's age or older, or it isn't about her age so much as her knowledge and wisdom, which are also highly respected in Chinese culture..  She might be like "a thousand year old" preserved duck egg which is really only maybe a hundred days old or less.

[g33k]

... or it isn't about her age so much as her knowledge and wisdom, which are also highly respected in Chinese culture ...

In that case, I'd expect a term like "Sage" or "Scholar" or the like, rather than "Ancient."