User blog comment:ChishioKunrin/Reminder: Weiss' Semblance is Glyphs, Not Ice/@comment-17099359-20141128203442/@comment-17099359-20141128210629

The problem is.Her not using them can be easily be explained by saying that she hasn't faced a opponent worthy of her using them since.The Grimm she faced were non threats,and the food fight wasn't a serious situation.

The point I'm trying to make here is that we don't have enough info to completely dismiss the possibly.And what info we do have is in conflict with what we have seen and what was said on the commentary.