In the evenings, while tending his own garden, Dickon begins to tell his mother, Susan Sowerby, about the new developments at the manor. The three children have agreed to let Mrs. Sowerby in on their jealously guarded secret because they regard her as being at least as trustworthy as Dickon. Dickon also tells his mother of the elaborate charade being carried on by Mary and Colin: these two must do a great deal of absurd play-acting so that Colin's improvement will remain a secret. They have, however, encountered a bit of a problem: they have both developed ravenous appetites, but are afraid to eat too much at the manor, lest they attract suspicion. Mrs Sowerby, much amused by this predicament, decides to send them fresh milk and bread to take the edge off of their hunger. Later, Mary and Colin send Mrs. Sowerby some of their pocket money so that she might procure fresh potatoes and eggs for them; they then roast these on the moor. The three children continue their "experiments" with magic: each day, they sit in a prayer-circle while Colin sermonizes to them about the healing powers of magic. Dickon asks Yorkshire's champion wrestler for an exercise program to make Colin stronger, and the trio begin to follow this program religiously. Colin grows healthier and more vigorous with astonishing speed&mdashmaking it all the more difficult to keep up his charade of illness.
The first half of this chapter concerns itself with the observations of the robin redbreast, which is watching all of the children's activities in the garden. He and his mate are sitting on their nest, waiting for their eggs to hatch, throughout the early part of spring. Colin and Mary are obliged to stay indoors on rainy days. At Mary's suggestion, they begin exploring the hundred rooms of the manor house. They remark that Mary no longer looks like the portrait of the girl and her pet parrot: she has been utterly transformed by the garden and the springtime, and is now quite pretty. Mary notices that Colin has drawn back the rose-colored curtain in his room so that the portrait of his mother is now visible. Colin says that "Magic filled his room" two nights before, and thus compelled him to pull back the curtain. Now that he is healthy, he feels that her laughter is meant for him, as a kind of unspoken blessing. Mary remarks that she has often thought that Colin is a great deal like his mother; it is as though he is "her ghost made into a boy." Colin is greatly moved by this idea, because it suggests that his father might become fond of him.
While Colin is lecturing in the garden, Ben Weatherstaff marvels at how strong he has become, and at how much he looks like his mother. Colin says that his experiment has succeeded, and that he intends to write a book about Magic quite soon. Suddenly overwhelmed by the miracle of his own health, he leaps up and shouts that he "shall live forever and ever and ever." Ben Weatherstaff suggests that Colin sing the Doxology (a Protestant Christian hymn) to express his joy and thankfulness. Dickon tells them that he and his mother believe that the skylarks themselves sing this hymn, which runs: "Praise God from whom all blessings flow, Praise Him all creatures here below, Praise Him above ye Heavenly Host, Praise Father, Son, and Holy Ghost. Amen." Colin immediately likes the song, and remarks that it means precisely what he does when he says that he is thankful to the Magic; perhaps God and Magic "are the same thing." Suddenly, Mrs. Sowerby appears at the garden door, and Dickon immediately runs to her. She is a beautiful woman with gentle, all-encompassing eyes; she wears a long blue cloak that appears very picturesque in the dappled sunlight. She, too, is taken aback by how much Colin looks like his mother. Mrs. Sowerby is full of affection for him, and calls Colin "lad" as if he were her own child. She also embraces Mary, exclaims of her prettiness, and compares her to one of her own daughters. The children show Mrs. Sowerby every part of the secret garden; Colin and Mary are irresistibly drawn to the "warm, supported feeling" that she inspires in both of them. Colin asks her if she believes in Magic, and she ardently replies that she does, although she doesn't call it by that name. For Mrs. Sowerby, it does not matter what its proper name is: it is merely "the Big Good Thing," the "Joy Maker." The group vows to make a visit to the Sowerbys' cottage. Mrs. Sowerby says that Master Craven must come home soon, so that he might see the dramatic change in his son. Colin is very touched, and says that he wishes that she were his mother as well as Dickon's. She embraces him and tells him that his own mother is present in the garden.
The rather odd interlude at the beginning of Chapter XXV, in which we observe the activities of the children from the point of view of the robin, provides the reader with indisputable proof that the robin redbreast is sentient, or conscious, with a mind of its own. In this way the narrator attempts to justify the personification of the natural world (the lending of human attributes to a nonhuman thing or an inanimate object) that occurs throughout the novel. The long-delayed introduction of Susan Sowerby is meant to fill the reader with the same eagerness and anticipation that Colin and Mary suffer. This is borne out by the fact that she remains undescribed until Colin and Mary see her; that is, we are to take her exchanges with Dickon in Chapter XXIV as yet another story of her. Since all Mary and Colin have had of her is story until Chapter XXVI, the reader is put in their position. Mrs. Sowerby appears to be aligned with the idea of motherhood itself: she adopts Colin and Mary on sight, and begins talking to them as though they were her own children. She lends them "a warm, supported feeling" unfamiliar to both of the motherless children&mdashthis, of course, is the feeling of being mothered. Mrs. Sowerby's way with children is presented as being uncanny: she is a "child charmer," as Dickon is an animal charmer. The narrator remarks, "It seemed as if she understood them [Colin and Mary] the way Dickon understood his 'creatures'." Mrs. Sowerby's blue cloak seems to align her with the Virgin Mother of Catholic symbology, who is always depicted as wearing a blue cloak; interestingly, Dickon's father goes entirely unmentioned in the novel. While the children's singing of the Doxology adds to the Christian associations of Magic, Mrs. Sowerby's talk on the nature of Magic suggest that Hodgson Burnett wishes it to be non-denominational. Susan says that it doesn't matter what name you call this force&mdashit is the life principle, which makes the flowers grow, and makes Colin well, and is responsible for all new lives (the world that each individual is.) It is a creator, of some kind, and all it wants is our joy. It is up to the individual reader to decide, of course, whether the idea of Magic can be disassociated from its heavily Christian Scientist underpinnings (which, at any rate, will be reinforced in the final chapter). The Magic is presented here as being extremely fertile, and is thus linked with the maternal person of Mrs. Sowerby and, by way of the secret garden, with the late Mistress Craven. By contrast, the stagnant world of the manor house is linked with Master Craven (and, by extension, with his upper-class masculinity). Both Mary and Mrs. Sowerby compare Colin to his mother; it is as though he were "her spirit made into a boy." She therefore goes on living in him, and in the garden, as Mrs. Sowerby suggests. Colin's decision to uncover the portrait can thus be linked to both his own and his mother's "rebirth."