[Gorwingel]

I would have to say Galadriel is more powerful than Elrond, just because of how old and wise she is. Elrond had actually been in Middle Earth for a very short time compared to Galadriel. When I read the Silm I was like "When does Elrond show up?" because I knew he was very powerful and all, he did not show up until over halfway through the book, and Galadriel was there in the beginning (well not the very beginning).
I also recall that there is one part in the Silm where it actually says that Galadriel was the most powerful and wisest elf in Middle Earth during the third age.