I wouldn't put a terrific defensive game as an asset for her, especially on the grass where's it hard to be defensive (see Wozniacki). I do think she can make it to the finals
I agree, it isn't as big of an asset as in clay for instance. But if you only had seen how she ran down Clijsters shots placed near the sidelines and returned those back near the baseline... Forcing an opponent hit a couple more tight shots can be VERY crucial.