·she buys so many clothes because she wants to be fashion(时髦

fashion本身就可以当名词,表示时尚.
这句话感觉还是应该是fashionable比较恰当.表示他想变得时髦.
如果用fashion,只能理解为名词,时尚
那就变成她自己想成为一个时尚了,有点不合情理.