Whenever Dickon isn't working in the secret garden, he's working in his own garden at home. After supper some nights, Mrs. Sowerby goes outside to speak with her son and admire his flowers and vegetables. In time, he tells her about Colin, Mary, and the secret garden. Mrs. Sowerby laughs when she hears that Colin is trying to keep this all a secret and so pretends to be ill. Dickon explains that the footman still carries Colin to his wheelchair as Colin tries to look helpless. Dickon notes that both children are gaining weight and Colin is getting scared that his appetite is going to give away the secret.
When Dickon lets his mother in on this secret, it shows the reader that there are parents out there who are trustworthy and care deeply for the welfare of their children and of others. Mrs. Sowerby's delight at hearing about Colin and Mary's antics suggests that she sees this as normal and healthy for their development, which indicates that she believes childish secrets like the garden are healthy and normal.
Mrs. Sowerby laughs again at this and says that in the mornings, she'll send Dickon with a pail of milk and fresh bread so Colin and Mary can keep their secret. She's right when she suggests that Colin and Mary find the whole thing highly entertaining. They get annoyed when the nurse and Dr. Craven ask too many questions, and one morning, Colin suggests that his appetite is bad and a symptom of bloat. Dr. Craven isn't convinced and says that Colin looks very alive, but Colin refuses to allow the doctor to tell Mr. Craven the good news.
By offering to send extra food, Mrs. Sowerby shows that she supports childish secret keeping in a major way. Especially in terms of Colin, this suggests that she understands Colin's desire to share the good news with his father himself and in doing so, invite his father into the fold and let him be a reasonable parent.
One evening, Colin miserably tells Mary that he'll have to have a tantrum at some point, especially if the adults keep talking about writing to Mr. Craven. He tries to eat less, but the breakfast is always so wonderful that he and Mary can't resist eating all of it. The first morning that Dickon brings bread and milk, Colin is beside himself with joy and declares that there's Magic in Mrs. Sowerby. As Mrs. Sowerby continues to send food, Mary and Colin realize that they're two more mouths to feed and so start sending money home with Dickon to help her out. Dickon also builds a little stone oven in the woods, which allows them to roast eggs and potatoes.
Just as when Mary thanked Martha for the jump rope and Mr. Craven for the gifts, the fact that she and Colin understand that feeding them might be a significant strain on Mrs. Sowerby’s pinched resources shows that they're developing empathy through their friendships with each other and are now more aware of other people’s needs. Specifically, the stories they hear from Dickon about his family help them conceptualize what life might be like for them and recognize the importance of contributing financially, which is fairly profound for two ten-year-old children.
Every morning, Colin leads everyone in his Magic ceremony, walks around the garden, and tries new experiments. One morning, Dickon returns from a few days away and explains he ran into Bob Haworth, a champion wrestler, and Bob shared some basic strength training exercises with him. Dickon shows the exercises to Colin, and both Colin and Mary perform them. The exercises soon become part of the day's routine. Thanks to Mrs. Sowerby's offerings and the oven in the woods, Colin and Mary start sending their meals back, much to the confusion of the nurse, Mrs. Medlock, and Dr. Craven.
The strength training exercises give Mary and Colin yet another way to exercise their bodies and engage with nature, as it helps them get stronger so that they can better engage with the natural world. The confusion of the adults points to the success of Mary and Colin's ruse at this point, especially given that, presumably, both children are looking healthier and have some color in their cheeks.
When Dr. Craven sees Colin after a two-week break, he notices that Colin looks well and perfectly normal. Colin answers that his earlier ravenous appetite was abnormal. At this, Mary starts to violently hack and choke. She later laughs with Colin about almost spoiling the secret by laughing. Meanwhile, Mrs. Medlock and the doctor wonder if there's some way for the children to get extra food. They discuss how well and happy they both look, and Dr. Craven says that they should be allowed to laugh.
Notice that in most cases, the novel links laughter with times when the children have to struggle to keep the secret. This continues to illustrate how positive the secret is for Colin and Mary, as it makes them laugh—something that even Dr. Craven understands is a good thing.