love

I'm sure it's quite useless to mention that an allegedly 'teenaged' elfling would have had the body of an eight-year old, as Elves didn't mature in body until about their fiftieth year.

Oh ye of little faith. Tolkien wrote that Elladan and Elrohir were born in T.A. 130, so they are about 38 years old, or the equivalent of 15 years old for elves (probably slightly older, since Elrond is part-human and his parents were only in their mid-twenties when they got married). Melpomaen is about a decade older, so 48 years old, the equivalent of about 19 years old for an elf. I'll add that to the author's note so that others aren't confused. I presuppose, probably incorrectly, that everyone remembers the twins were born in T.A. 130!