In The Secret Garden, Mary Lennox is depicted as a girl who never had the chance to become close to her parents and barely knew them. This is partly attributable to the time when the book is set and the class of the Lennox family. The Secret Garden was published in 1911 and is set at around the same time, and the Lennoxes are wealthy people who live in British India. It would be normal for such a family to have large numbers of servants, including an Ayah, or nanny, for their child.
However, it appears that the Lennox family is cold and lacking in affection even by the standards of the time and place. Mrs. Lennox is a beautiful woman who enjoys social life and does not want to be burdened with a child. Her father is equally distant. The result is that Mary is materially spoiled but never receives any love or attention from her parents and is brought up entirely by the servants. When her parents die, she does not have any connection to them that would cause her to grieve or miss them. Later in the book, when she meets Colin Craven, Mary quickly recognizes in him the combination of material privilege and emotional starvation that characterized her own childhood.