I also don't think that "you know that meaningless ruin from the first zone? That was actually your home!" would be a very interesting reveal. It's just an empty husk.
Okay, perhaps I'd better put the pivot in career to video game writer on the back burner for now

You right to say that 100 year old half elf would look like she were in her 40s or 50s
Really? I was thinking late 30s based on a half-elven lifespan of 180 years vs a human one of ~70 and the guess that, as with the maturing process, the aging process for half-elves was of a similar duration to humans and it's the bit in the middle that's stretched out. But as you know the FR lore much better than I do, I guess I need to revise that. Plus I think 180 might be really old for a half-elf, so not comparable with 70 for a human. But while I'd put SH at mid-thirties if she were a human, I wouldn't say forties is out of the question as I don't think she looks
all that much younger than me. But I'm probably fooling myself about that just as much as that there's a snowball's chance in hell that my outside bet will turn out to be true. And anyway all that comparison ignores that folk probably have harder lives in Faerun so could look older than a modern, western Earthling of the same age, even if Faerunian life expectancies don't sound mediaeval.
Despite everything, I nevertheless refuse to give up on my pet theory entirely until I play the game and find out what SH's real story is. And of course everyone else has the right to cling to theirs just as fiercely
