Zelda can' do anything for beans. Also Snow, the computers are idiots anyways. They only make good meat shields. I did Melee with four computers against each other. They took 20 minutes to finish with 5 lives.
Well that still true ... i already did a one vs one (two computers) max level 20 lives ... this took almost one hour -_- (on Melee but i can imagine that on Brawl.)
I personally believe Zelda would win becuase of the fact that she seems to always be able to control some form of magic in all her games, magic which could seriously injure Link.
let me break it down. For one thing link has (what seems to be) an obbsession of zelda. The only reason would be that link would get frusterated that zelda hasn't asked him out to the diner yet (LOL). Then link would maybe severly injure zelda, she turns into shiek, and they both lose. . .why? because link would be filled with needles and chain scars while zelda has several cuts and bomb singes. . .and bruises by the boomerang. . . HYAAA!
They would never fight each other in the first place (except for when zelda gets possessed by ganon, like in the first stage of the final boss battle in TP).