Audrey, unfortunately, is a little distracted, and does not notice the soft golden glow. "...Um!" comes her very informative reply. She stomps and stomps with her boots at the vines, suddenly very aware this is a bad thing. She knows how to freeze these, and she has a Patronus, but neither are available because neither is her wand. She reaches blindly for the bookshelf, or something heavy, hoping to knock it down to smash the plants. An inelegant solution is still a solution.