This is a masterpiece, and NEVER in my life did I mean it as I do now.
Our main character is a woman possibly suffering from postpartum depression, with the possibility of phosphorus poisoning from the knuckle pills, which explains the fall into delirium and the obsessive thoughts.
The description of wallpaper leads us to think that it most likely contained Arsenic, as most pigments did at the time, leading the previous children to tear the paper. The transparency that is described however may indicate the use of Turner's yellow, which I am no painting expert or historian, but was made with lead and may also lead to lead poisoning, as indicated by the thick air and scent that hovered over her from the deteriorating paint.
When first met with the wallpaper, it disgusts her, and as she continually observes it, she comes to accept it and understands it. her obsession with the wallpaper intrigues her family, but they fail to understand it as she does. You can also see the motherly love in her when she decides she would rather suffer it than her child.
The yellow wallpaper with the white bulbous patterns and patches speaks of the restrains placed on women at the time. the women escape at night which is the time that her family is asleep while she stares at the wallpaper. When it is daytime, she is quiet and so are the women, but they continually stare at her as if Calling her to set them free (set herself free), and they crawl around the property as she does, always in the shadows. At last, she joins the women in the wallpaper.
Last but not least, her husband is a shyt doctor.