Well no doubt there are better ways to say this... but here of course I am trying to reinterpret a statement so that it might allow both it and RGEO to fit (well enough if not perfectly) into the history of Celeborn and Galadriel, and so I can't change the wording.
So so far I'm sticking with the Ered Wethrin
I think it's a bit odd to have Galadriel say this if she means she went to Lindorinand
without Celeborn and returned... I mean why note this crossing if being together is so much a part of the meaning?
In other words, as a detail of history it works well enough, but not so much with respect to the context of Galadriel's statement. My scenario is a bit off too due to the timing of the 'fall', as I say, but at least it puts Galadriel with Celeborn together after this crossing, and doesn't seem to step on what I feel is a main thrust of the statement.