We know they age to a point, the same as humans, Sylvanas was a fully fledged Farstrider aged 20,(We don’t know -when- that was, but we do know she was an adult at the age of 20) whereas Vereesa was too young to have served in the Second War, so presumably late teens (I mean you’d hope so, or her relationship with Rhonin takes on a deeply troubling aspect) We know that Lor’themar, Liadrin, Halduron and Dark’han Drathir, as well as the other dude whose name I always forget served in the Troll Wars, as did Alleria, and those ended 2,800 years ago. We know Lor’themar was a Lieutenant at that time, and Liadrin a Priestess, so again, adults. We know that since they are not Immortal anymore, that Night Elves (and presumably Nightborne by extension) have “The Same lifespan as High and Blood Elves, that being several thousand years”. We know that Lor’themar’s hair colour is his natural colour, not due to age.
Alleria must have been at least 2,820 by the time she went through the Dark Portal, we know that “A Thousand years of War” actually meant that span of time for those involved, and that unlike Turalyon, she was not Lightforged so immortal, so we know that she is currently at least 3,820, and still seems pretty physically chipper (This is pre:Void consumption).
We know that Lorash Sunbeam is supposedly of the first generation born in Eastern Kingdoms, but before the High Elves had founded Quel’thalas, this makes him at least 7,000 years or so.
All of this is consistent, because of the use of the word ‘several’. As in ‘Several thousand years’. You only use the word ‘Several’ to mean 3 or more, but less than 10.
We also know that since their immortality wore off, some of the older Night Elves are dying of sickness or age, but that they are basically picking up from where they left off, when they became immortal, the years they ‘cheated’ are not suddenly piling on them, or Tyrande, Malfurion, Thalyssra, Elisande and co would all be dead now.
We can therefore, say with current lore certainty that elves live at the very absolute least, 3,000 years, at the most 10,000, and it seems likely to be closer to the 10,000 than 3,000, as Liadrin, Lor’themar, Halduron and Alleria all seem to be perfectly spry, and Lorash at 7,000 or so was able to physically take on Malfurion (even if he then died in that combat)
Basically the age you have selected for your elf sounds perfectly possible, and completely within the lore guidelines we have.
