It makes me nervous too. I would guess... since the graffiti was erased, she's probably trying to find another way of carrying out her plan.

[thinking about it...]

It was relatively late in the timeline that you all managed to erase it, so she'll have only had a short time to consider other options at this point. But we should be on our guard. If she's feeling cornered because her weapon didn't work out, there's no telling what she'll try next.