I dunno, Ent, I'd still have to talk with someone who actually did it. Or else SEE a woman fight successfully with a Claymore. For several reasons.
1) swiging a large sword is a very different kind of muscle strength than the endurance of carrying a load. If you don't think so, I challenge you to do 50 reps with 150 pound curls. After you've rested, try carrying a 150 pound weight for fifteen minutes. Both will probably make you tired, esp if you're not used to it, but the reps will wear those muscles out more. You'll also find that the aches are in completely different parts of your body.
2) There's the whole going up against men thing. A claymore isn't a delicate, stylized weapon, whatever the weight. It's a club with a cutting edge. That means it's strength against strength. And as Skar has pointed out before most women will lost against most men in such a contest. The shock of blocking blows alone will wear them down eventually, leaving them less capable of blocking more. This is the sort of fight where women would be inherently less capable.
3) It's not as much of a factor as MoD pointed out, but because it's aerodynamic does not ELIMINATE air resistance. And as a bigger object, it's going to have more air resistance than a smaller object of similar design.