Actually

That's not THAT hard - Anneza could have some ability to sense where that kind of material is, since she can "weave" it, so she could find the material. There IS, however, the matter that Julian is effectively more powerful in a fight than Anneza is, so there should be some way to resolve that. Preferably without any involvement by Lucas to prevent her from cheapening the story too much by being the problem solver for every little matter.