[Shin-ah's disappearance left her distressed as it is, not realizing about the feathers or that her own memories are indeed missing -- stumbling around from the disorienting feeling of it. Does she come in maybe hoping to see Ao chewing on flowers with Shin-ah in tow after all? Seeing Arthur has her stop short, just as he's touching the light.
And oh. It comes back to her with the brunt of the feelings it shares with him. When she started to learn all the difficulties the entire country was struggling with and how much King Il was hated, while she was still mourning him.]