I don't get why everyone is so upset with her, she was worried so she went in. Alot of times people need a shove or shock out of the regular to move on and grow from events. If she had not entered the room, the plot wouldn't really be advancing, we wouldn't find out more about Nan's issues and over come it. Honestly I don't really see the issue with how the Author decided to move the story forward.
I am so glad I decided to read this manga, its so complex and detailed about everything, you expect one thing to happen but in the background something else occurs to change the whole outcome. I especially love the complexity of each character and their situations.