I've watched this a few times and I can't decide if she makes them appear or if they're just enchanted and otherwise already present. They seem to be firing Arcane salvos either way, though; so she seems to be doing more than just manipulating them if they're not conjurations altogether. It's six of one and a half-dozen of the other, to be honest. Impressive bit of magic either way.
At 1:06 - 1:07 they do appear to half not be there - and they also appear to be translucent, so I'm kind of leaning toward the notion that they're conjured and not just manipulated.