Mary's first few days are all the same. She gets up, eats breakfast, and then goes outside. The narrator notes that Mary doesn’t realize that this is actually the best thing for her, as the moor air puts color in her cheeks and is invigorating. After a few days of this routine, Mary wakes up and knows that she's truly hungry. Martha insists that this is because of the moor and encourages Mary to play. Mary notices that Ben Weatherstaff seems to avoid her, and she spends most of her time walking outside the gardens, where ivy covers the walls and everything seems neglected.
When both Martha and the narrator insist that Mary's improving complexion and overall health is the work of the fresh moor air, it again suggests that not only is nature the best thing for a child, specifically English nature is best—this claim of English superiority bears the stamp of the time period, as British imperialism (and all the ethnocentric attitudes that accompanied it) was nearing its peak. Mary's draw to the neglected part of the gardens mirrors now neglected she feels; she's drawn to a place that reminds her of herself.
As Mary studies the bushy ivy, she hears the robin singing. She greets the robin, and in reply, the robin chirps and hops around. Laughing, Mary runs after the robin and tries to whistle. The robin settles in a tree, which Mary realizes is in the garden without a door. She runs back to the kitchen gardens and into the orchard and decides that the tree the robin is in is indeed the same one she saw him in on her first day at the manor. She makes another lap around the gardens and thinks it's strange that she can't find the door. Mary realizes that though Ben Weatherstaff said there's no door, there must be one since Mr. Craven buried the key.
Playing this game with the robin, laughing, and then becoming very curious again shows that having a friendship with any being, animal or human, can have a profound effect on a person. Notice how the fact that the garden is supposed to be private and a secret makes it all the more interesting for Mary. This begins to show that for children, secrets are like joyful games, as Mary delights in unthreading the mystery of the secret garden.
Mary stays outside all day and, for the first time, feels glad she came to Misselthwaite Manor. The narrator explains that the fresh moor wind is blowing "cobwebs" out of her brain and waking her up. By the end of the day, Mary is pleasantly tired. After supper, she asks Martha why Mr. Craven hates the garden. Martha is happy to sit with Mary and talk. She instructs Mary to listen to the wind "wutherin'" and finally starts her story. She reminds Mary that Mr. Craven has ordered that nobody speak about the garden. Martha says that Mrs. Craven made the garden, and she and her husband were the only ones allowed in to tend to it. Because she was so small, Mrs. Craven often sat on a tree with roses growing on it, but one day, the branch broke and she died.
Again, per the novel's logic, Mary is improving because she's in England and is getting to spend time outside; simply spending time outdoors in India wouldn't have had nearly the same effect (recall that her sickliness as a child was actually attributed to the fact that she was born in India). When Mary asks Martha to talk to her, it shows that she's beginning to think of Martha as a friend she can connect with rather than hired help who exists purely to cater to her. This shows Mary beginning to think of others outside of herself and appreciate them for the things they have to offer—especially when those offerings include information on a compelling secret.
Mary sits silently and notices that she's feeling sorry for someone for the first time. Then, as the wind blows, she hears a strange cry from somewhere within the house. Mary tries to point it out to Martha, but Martha insists that the house makes strange sounds. Suddenly, the wind gusts through the house and blows open their door, making the sound easier to hear. Martha shuts the door and insists that if it was anything, it was the scullery maid crying about a toothache. Mary doesn't believe her.
Feeling sorry for Mr. and Mrs. Craven further indicates that Mary is beginning to think of others outside of herself and is therefore becoming a better person and friend. On another note, Martha’s hasty excuses about where the crying sounds are coming from suggests that she’s lying, while Mary's skepticism in the face of Martha’s flimsy explanation suggests that more secrets abound at the manor than just the one regarding the secret garden.