Bethberry, that's food for meditation...
A couple more thoughts simmering:
#1. Did Luthien have a grave? (Did Beren?) I can't remember (No Sil here at work.)
#2. What is it about the removal of her grave to a "green" place? As opposed to a stony place, Gondor. There's some ontrast here between elf and man (there must be) but it's ... not... clear yet.
Her relocation also strikes me as so very odd, because I am so used to the (Christian) concept of husband and wife being buried side-by-side. Why? Because they are *waiting for the resurrection.* Who do you want to be the first person that you see when you are raised from the dead? Your beloved, of course. It makes sense. Hence, JRR and Edith are buried Side By Side, (As Beren and Luthien... hmmm, see question #1.) So, of course, are all my (known) ancestors, buried side by side with their spouses. It's a very common thing.
But I guess it's not all that common in Middle-Earth. Firstly, there's nothing said about a resurrection; the focus is on "Beyond the Circles Of The World." But besides that, the Kings seem to be buried alone. Where did their wives end up? (cue Lush & Bethberry's lament for unsung women.) Likewise in Rohan, there is no indication that the king's burial mounds included their wives.
I understand if one dies on the battlefield. But such is not the case here.
Come to that, what do you *do* with a dead elf? Aside from leaving them simmering in the dead marshes, I can't recall any elven gravesites.
Further thoughts: Where in the Trilogy is there ever mention of a woman's grave? What about the Sil? Even Niniel leaps to her death; I don't recall a mention of a grave??
Did Tolkien perhaps have some aversion to thinking about a woman's death, or a woman's grave? Is it connected with the matricide issue, I wonder? Or have I just forgotten a list of women's graveites? (Entirely possible.)