It is said that Galadriel is the equal even if unlike endowments of Fëanor by Tolkien himself in the unfinished tales. We all know what is said of Fëanor, so she must be crazy powerful, we only rarely see it. There are some tidbits like throwing down walls and sending a mist to protect Eorl's host.
Galadriel was the greatest of the Noldor, except Fëanor maybe, though she was wiser than he, and her wisdom increased with the long years.
Her mother-name was Nerwen ("man-maiden"), and she grew to be tall beyond the measure even of the women of the Noldor; she was strong of body, mind, and will, a match for both the loremasters and the athletes of the Eldar in the days of their youth. Even among the Eldar she was accounted beautiful, and her hair was held a marvel unmatched. It was golden like the hair of her father and of her foremother Indis, but richer and more radiant, for its gold was touched by some memory of the starlike silver of her mother; and the Eldar said that the light of the Two Trees, Laurelin and Telperion, had been snared in her tresses. Many thought that this saying first gave to Fëanor the thought of imprisoning and blending the light of the Trees that later took shape in his hands as the Silmarils. For Fëanor beheld the hair of Galadriel with wonder and delight. He begged three times for a tress, but Galadriel would not give him even one hair. These two kinsfolk, the greatest of the Eldar of Valinor, were unfriends for ever.
Galadriel was born in the bliss of Valinor, but it was not long, in the reckoning of the Blessed Realm, before that was dimmed; and thereafter she had no peace within. For in that testing time amid the strife of the Noldor she was drawn this way and that. She was proud, strong, and selfwilled, as were all the descendants of Finwë save Finarfin; and like her brother Finrod, of all her kin the nearest to her heart, she had dreams of far lands and dominions that might be her own to order as she would without tutelage. Yet deeper still there dwelt in her the noble and generous spirit of the Vanyar, and a reverence for the Valar that she could not forget. From her earliest years she had a marvellous gift of insight into the minds of others, but judged them with mercy and understanding, and she withheld her goodwill from none save only Fëanor. UT
So it seems she has an extraordinary ability to see the minds and intentions. In the fellowship of the ring she stated that she is able to read the mind of Sauron, at least all that what concerns the elves, but he can´t see hers, even if he tries. Furthermore with Nenya she is able too keep all evil out of Lorien, unless Sauron had come there himself.
She was a strategist too, wanted to establish an easternmost outpost in Lorien, left Beleriant in the first age to unite wood elves and men and . All this is written in the unfinsihed tales.
So, with Galadriel it´s not that obvious at the first sight, but if someone looks deeper in the text, one will recognize her powers.
In my humble opinion, Galadriel is greater than Fëanor, Tolkien seems to be unsure regarding that matter, but I think she´s greater, being maybe even the inspiration for the Silmaril. The only elf being greater is Luthien.
