At the beginning of the story, the main character narrates her surroundings. She explains that she is being taken to an isolated place, an old estate, which has been in turn taken by her husband.
It is very seldom that mere ordinary people like John and myself secure ancestral halls for the summer.
A colonial mansion, a hereditary estate, I would say a haunted house, and reach the height of romantic felicity but that would be asking too much of fate!
By saying "securing ancestral halls for the summer" refers to the tradition of retiring to the countryside during the summer. Those who do not own their own summer estates would rent one to rest there for the time being. The ancestral hall to which she refers is probably a big estate which used to belong to an upper class aristocrat, and who probably lost it, or has to rent it out for profit.
Our main character has just had a baby and see seems to be suffering from a case of post-partum depression. This particular reason is why her husband procured this ancestral home, in their case. However, our narrator is clearly not very happy. She will be isolated and put to a "rest" cure where she will not be able to write, draw, or do anything BUT lay around all day, taking medicines, and making sure to stay out of everyone's way. This is what will ultimately lead to her final breakdown, where she will rip the wallpaper to supposedly liberate "a trapped woman" that lurks beneath it.