Eowyn, daughter of Eomund, Shieldmaiden of Rohan, is easily Tolkien's best, most fully-realized female character. Arwen is too two-dimensional and while the recent films tried to give her more to do, in the books she pretty much did nothing but serve as Aragorn's Madonna. Galadriel is regal and distant. And where do you go from there? Rosie Cotton? Goldberry? Frodo?
Heartsick and yet unbroken, Eowyn dwells in her uncle's house at Meduseld before the coming of Gandalf, watching in furious impotence as the end of days gather about her. Her once-doughty uncle Theoden is reduced to dotage by Saruman's magics and the fetid whisperings of Grima Wormtongue, who will be getting a call from HR any day now for his unwanted sexual advances toward her. She longs to take part in the great struggle that dominates her epoch, to be more than a nursemaid to the young and infirm, to do great deeds, to make her life a song of meaning. Her great terror is "to stay behind bars until use and old age accept them and all chance of valor has gone beyond recall or desire."
She sees her chance when Aragorn and his companions arrive, and begs to accompany them, only to be shunted aside, both from the great work of men and Aragorn's affections. Isildur's heir friendzones the shieldmaiden, even though her feisty temperament stirs his blood as much as Arwen's glacial beauty ever did. Apparently Tolkien considered pairing them off, but chose bigger and better things for Eowyn.
Thumbing her nose at those who would send her back to her cage, Eowyn rides to battle and proves pivotal in her combat with the Witch-King of Angmar. It is foretold that no man can slay Sauron's great lieutenant, but he learns to his dismay that it is no man he faces, but a woman. Her moment of valor and triumph nearly claims her life, but it also lifts the clinging fear and despair from her heart, creating an opening for Faramir when both are patients in the Houses of Healing.
The thirst for glory and a life of meaningful service can exert a powerful magnetism on a soul, as can the gnawing terror that with each day that passes, the likelihood of such a life recedes from us like the inexorable tide. Eowyn is lucky. She finds both the impact and the love she seeks, though neither in the places she first looked for them. Maybe that's the secret - to keep looking, to push past the failures and the disappointments, to stay open for that lightning strike that may come even at the ending of the world.