these comics elaborating on how lifespan differences are perceived in-universe are really interesting when you apply them to thistle's family situation. since it's been established that long-lived peoples tend to infantilize the short-lived, and this is a norm that persists to the current day, this would also hold implications for how long-lived peoples regarded these relationships in thistle and delgal's time
if we're going by the average 200-year lifespan of modern elves and assuming that hasn't changed much in the last 1000 years, then the melinis existed around 5 generations prior to the present, and certainly that would imply a more "medieval" perspective on these issues, where even an elf as young as thistle would still be considered a senior to tallmen more developmentally advanced than him
it's likely that, with how adultified thistle was, he was legitimately considered an adult (at least relative to tallmen) simply because he was an elf - he saw himself as such, the tallmen around him saw him as such, and where this gets interesting is how long-lived races would perceive his abuse, because i'm willing to bet they would also have seen it (and probably would still see it) less as person-to-person abuse so much as a case of a kid being raised by wolves (in terms of both "primitiveness" and lifespan disparity)