I'm always delighted to find Cuiviénen stories because they offer such interesting takes on the prehistoric Elves, and yours definitely didn't disappoint. I was a little confused about the reasoning and ability of abandoning children to the forest and wiping their memories, but it makes sense as a sort of rite of passage, and especially considering it a mirror of the origin story in the Silmarillion. Finwe the innovator struck a chord with me as well.

All in all, I enjoyed this a lot, and the formulaic nature of Míriel's knowledge (and some other details) interspersed into the text gave it a nice touch of repetition and an oral narrative - very fitting for the era you picked to write about.

This reminds me a little of one of the later stories by Ursula LeGuin set in her Hainish universe (I've forgotten the title). Your story is rather more optimistic than hers, though.

Except that Miriel's expectations in the final paragraph aren't really fulfilled, are they?

What a vivid, creative picture of the Cuiviénen era.  I think it was a good choice to view these things from Miriel's eyes, as she will end up bearing her child and fading away in a world and culture far different from the one she's come to know.  Hers and Finwë's refusal to accept "because it's always been that way" as a reasonable explanation is endearing (I love characters that question), and seems very appropriate to the progenitors of a particular Noldorin family line.  I liked the complex use of the cloaks, too.

(About the rite of passage - For a moment I thought it was rather horrific, but it occurred to me that perhaps the first generation, who really did awake in the forest with no prior memories, might have assumed this experience was a normal, healthy, and required part of life..)