Just catching up to the thread. 
So I just started another Lavellan playthrough (second Lavellan)! My first Lavellan was a mage but if I'm being honest I think enjoy archery for my canon Lavellan the best. I think it makes more sense for her to be a mage but this is the first game I found archery fun. Maybe is the fact that you can move while you shoot suckers in the face, I don't know.
My headcanon is kind of fuzzy but she's a hunter. Did anybody else do rogues or warrior for Lavellan? I know most people here play as mages but my favorite classes are always warrior and rogues. It's just that in terms of the story, it made sense for Lavellan to be a mage? I just don't think I enjoyed it as much.
What are some of your headcannons for non-mage Lavellans? I even think mine can barely read. Wouldn't that be something taught only to the First? I don't know if there's any codexes about it, it kind of feels right. I'm just worried that they won't have a lot in common since she's not mage, y'know? What would be her reason in being interested in the Fade? I know she would be interested in knowing about her culture~
Ooh! Headcanons again!
I've talked about mine before so I'll just copy-paste some of it here:
Tala is an archer and hunter for Clan Lavellan. She strived to be one of the best hunters in the clan, making sure that they have enough to eat and to make sure they are protected from anything or anyone that threatens them. She sometimes wishes to venture outside the clan, and hopes that one day her people would reclaim some of their lost culture.
She has a twin brother (my male Lavellan, Riel) who is also the clan's First and they are both very close. Hanging around him made her fascinated with magic even though she's not a mage. Take note that she is more fascinated with magic than actually wishing she had magic (she doesn't trust herself to wield that kind of power). She loved it when her brother would reiterate to her the ancient elven lore that Keeper Deshanna told him, which is why Tala then gets fascinated with Solas' stories. She might have seen a bit of her brother in him.
Also, I imagine my Lavellan had an admirer back in the clan, a Dalish warrior who wished for her hand in marriage. But she wasn't really interested in settling down just yet and so when Keeper Deshanna planned on sending someone to spy on the conclave, she volunteered. She just wanted something exciting to do in her life before marriage happened. (And boy, did she get it.)
As for literacy, I always headcanon that the Lavellan clan is a bit odd and during the times when the clan gets to trade with the humans, they would occasionally take in human literature. Tala would often read these human books, inciting her thirst to venture out of her clan (and they may have made her into a hopeless romantic). And I’d like to think Riel may have taught her a thing or two about writing.