Tolkien's female characters, though they may be in the background compared to his male characters, often have a depth that some writers have trouble getting in their main chracters.
Considering Tolkien's Catholic background, I'm not suprised at this depth and his deep reverence for women. After all, look at these role models of Catholic ( and Biblical ) women:
Queen Isabella of Spain, who rode to the battlefield dispite pregnancy; Saint Catherine of Siena, who persuaded a pope to return to Rome instead of remaining in a luxurious French court; Saint Joan of Arc, whose deeds I need not name; Jael, who killed a Syrian general by pounding a tent stake into his head ( yikes! ); hundreds of martyrs who endured torment and death; women who dedicated their lives as nuns to the service of God and man, sometimes to death ( nursing nuns who died of disease, ect. ); and millions of women who raised children to become decent citizens of society.
There's a LOT more women I could write about, but I digress...
I think that a good example of Tolkien's view of women can be found in LOTR, when Tom Bombadill and Goldberry were serving dinner to the hobbits. They move in a different way, yet the actions of the one complements the actions of the other.
And yes, we women do possess such a thing as "the strength of weakness", and it's far braver to be a women to the full than anything else.