Lords and Ladies of the Rings

[the phantom]

Tolkien does not seem so sure that they would be capable

Yes, very true. That's why I made my last statement conditional on the last line- "if Galadriel really could".

And I, for one, don't think she could have. I don't think she could've come close to beating Sauron. Whenever he's been defeated, it's always been just physically. He always pops up again. Given enough time (maybe 200 years, maybe 2000 years) the ring would completely bend Galadriel (or most anyone) to its will (Sauron's will) and then Sauron would return and they would be subject to his command.

At least that's the way I always envisioned it.