How many children does Galadriel have?
It is Mothers' Day today and I wanted to post something, so here is a shortish post collecting together my thoughts on this question :)
As with so much re: Galadriel there is a short answer and a long answer, and the short answer is “one, obviously”, and the long answer begins with “Well...”
In the published LOTR, the only child mentioned is Celebrían. Given that Tolkien only invented Galadriel while writing LOTR this is probably the original idea and it's the one Christopher went with when composing the Silmarillion. But, in Unfinished Tales where you see more of the different ideas for Galadriel's Second Age story that he wrote afterwards(? we presume), Amroth is also the child of Galadriel and Celeborn, and when Galadriel passes through Moria after Annatar and the gwaith-i-mirdain stage a coup she's 'taking with her Amroth and Celebrían'.
Christopher says of this:
The text is much emended, and it is not always possible to see what belongs to the time of composition of the manuscript and what is indefinitely later. This is the case with those references to Amroth that make him the son of Galadriel and Celeborn; but whenever these references were inserted, I think it is virtually certain that this was a new construction, later than the writing of The Lord of the Rings. Had he been supposed to be their son when it was written, the fact would surely have been mentioned.
By the late 1960s JRRT seems to have gone back to considering Amroth the son of Amdír.
But then, when Nature of Middle-earth was published it contained more notes of Tolkien trying to figure out the years of birth of Galadriel, Celeborn, Amroth and Celebrían, and the considerable tangle he was trying to unpick regarding when elves have children and when Amroth (as the first child of Galadriel and Celeborn) could fit into his narrative while leaving room for Celebrían. And this is where we find out he also considered a compromise to this where Amroth was the son of Celeborn from an earlier marriage:
As first written, before most of it was struck through, this concluding sentence (after the colon) read: "The following calculation is probable. Celeborn's wife [?stole] away and left him with a son, Amroth." In conjunction with this, it appears that the following footnote was supplied:
The Elves did not normally marry again, but after the judgement of Míriel they were permitted lawfully to do [so] if one partner deserted the other. This very seldom occurred; but in such a time of divided feelings as [the] end of [the] First Age this could occur.
But then Tolkien struck this out, leaving us with nothing more than a lot of intriguing possibilities to explore in fanfic :)
So. The answer to how many children Galadriel has is: One - No, two - No, one - No, one plus a stepchild from her husband's first marriage - No, just one.
But finally! Back to LOTR, and Treebeard's greeting to Galadriel and Celeborn:
A vanimar, vanimálion nostari!
Which Tolkien translates (in Letters) as 'O beautiful ones, parents of beautiful children!'
I was going to treat this as conclusively "she has more than one child, at least as far as Treebeard is concerned", but then Parf Edhellen translates Quenya 'nostari' not simply as 'parents' but also as 'ancestors'. So: back to "one child" or at least "not necessarily any more than one child".
But finally! The whole reason for translating 'nostari' as 'ancestors' there and not simply 'parents' is because:
the couple to which the phrase Q. a vanimar, vanimálion nostari was addressed (Galadriel and Celeborn) had only a single child, and so the phrase only makes sense if it refers to them as ancestors of all of their descendants: their daughter Celebrían and her children Elladan, Elrohir and Arwen.
Which is a fine and coherent way to reconcile "they only have one child in LOTR" with "Treebeard speaks of them as parents of children, plural, in LOTR" I suppose - but is not the only explanation. And Tolkien translated that greeting of Treebeard's as "parents of beautiful children", not "parents-and-grandparents-and-ancestors of beautiful children".
Maybe Treebeard just forgot. Or maybe they end up having other children post-LOTR and he foresaw it. Or: maybe there are more children, and always were, and Ents know better than we do...