Answer:
1.A mentally ill young woman, possibly named Jane, who´s suffering from “nervous depression” or most likely postpartum depression.
This point of view is necessary because the whole narration comes from her journal, which she has been forbidden from writing on, and which she uses as a way to ease her mind. However, that same point of view helps the reader realize that she´s falling deeper into her illness.
2. At first, the narrator seems perfectly reliable, despite her mental condition. However, as her fixation on the yellow wallpaper grows, the reader learns that she´s falling deeper into her illness, becoming less and less reliable. By the end, nothing she writes can be considered as part of reality.