The Lady Galadriel is like the female version of Elrond: ancient, wise, Elvish, and a possessor of one of the Three Elvish Rings of Power (in her case, Nenya, with a white stone "like a frosty white star" (6.9.67)).
But she may be even more perceptive than Elrond; she's certainly smarter than her husband, Celeborn the Wise. When Treebeard asks if he will ever see Galadriel and Celeborn again, Celeborn says he doesn't know, but Galadriel answers with certainty: "Not in Middle-earth, nor until the lands that lie under the wave are lifted up again. Then in the willow-meads of Tasarinan we may meet in the Spring" (6.6.67). She is always two steps ahead. After all, she is also the source of the prophecy that, once Legolas hears the Sea, he'll never be content in forests again. And she is the one who advises Aragorn to seek out the Paths of the Dead.
Galadriel isn't just good at making predictions. She is also an excellent gift-giver. The Phial of Galadriel, the glowing jewel that she gives to Frodo in Lothlórien, saves Frodo and Sam's lives in Shelob's Lair at the end of The Two Towers.
But interestingly, when Sam tries to use the Phial in Sammath Naur (inside Mount Doom), it gives a pale and sickly light. At the heart of Sauron's kingdom, even Galadriel's great power can't win out. The Phial of Galadriel has been an excellent tool against the dark up until this final showdown at Mount Doom. But the sudden lack of light that the Phial gives out indicates that even Galadriel can't help now, and Sam and Frodo have to do this thing on their own (with a little help from Gollum).
But Galadriel is more than just a prophet and a gift-giver; she is also a grandma. Yep, that's right, Arwen Undómiel is Galadriel's granddaughter through her daughter Celebrián. It's a little strange to imagine this fair, eternally young-looking woman as a grandmother. We guess that's yet another reason why it's great to be an elf.