[Dragaera] long-lived dragaerans

[J C]

So, we know of Sethra being, shall we say, somewhat old. 
 
And the Necromancer has a slight number of years beneath her belt, that's for sure.
 
But Sethra is a vampire.  And the Necromancer is a demon.
 
What/who are the Sorceress in Green, and Sethra the Younger, then?  If not StY, then definitely the SiG.
 
We know that there are beings that live for VERY long times who don't quite fit the definition of "immortal" or god.  Arra, for one, is particularly long-lived.  So is, for that matter, the coachman who shows up quite frequently.  And we don't know exactly what Devera is much less how old she should be, or why she's pre-manifested as a six year old girl as opposed to the mature woman she'll presumably become after Aliera gives birth to her.
 
Anyone got any ideas on any of these people?
 
Jon
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