I saw the woman as Rosie (but why not any other descendant who is up late with a fussy baby?)

The youth is definitely an Elf. In my head he sees the mallorn in the party tree and gets homesick for Lorien, and ends up in Bag End's garden because Sam has sown other flowers he recognizes and therefore receives hobbity hospitality. But whether home is East or West is up to the reader.

It's kind of neat seeing how differently people are reading this one.