They could draw it. But...powering it? No.

[She rolls her shoulder in a half shrug, and gives him a serious look.]

What you write doesn't matter so much as the intent behind it. But you still have to know how to channel the will to give it energy. That takes training. At least for something this big. Something simpler? Well, anyone could manage that, for a smaller area. Say...you could probably ward your door with a little effort.