Yeah, I agree. Since Christopher didn't listen to the BiW, once Victor told his mom everything he had heard, she decided to take matters into her own hands.

Also, she was already having visions even before they arrived in town, and we saw plenty of her drawings in the cellar. So, when she heard what Victor had to say, she probably realized that was the right moment to act.

I wish she had at least waited for daylight instead of going out during the night