The threefold scheme, one Goddess understood through Maiden, Mother and Crone aspects tied to the waxing, full and waning moon, owes its popular modern shape substantially to Robert Graves' The White Goddess (1948), a work of poetic and mythographic argument rather than historical scholarship, published before Gerald Gardner's Wicca reached public attention. Gardner and, more decisively, Doreen Valiente centered the Goddess in Wiccan liturgy in the 1950s, and the Maiden, Mother and Crone framing was taken up and developed further by later Goddess centered Wiccan and Pagan writers, most influentially Starhawk's The Spiral Dance (1979), which shaped the Goddess centered, feminist leaning strand of the tradition sometimes called Reclaiming.
Ronald Hutton's history of the movement traces this reception in detail: Graves' triple goddess is a literary construction assembled from a wide and selective reading of mythology across unrelated cultures, not a scheme any single ancient religion held in that form, and its adoption into Wicca is itself a documented twentieth century event rather than a survival from an older triple goddess cult.
Individual Wiccan traditions differ on where the boundaries between the three aspects fall and on whether they map strictly onto biological stages of a woman's life or function as symbolic postures available to any practitioner regardless of age; Dianic and other feminist-influenced lineages in particular have pushed back against a strictly biological reading, treating Maiden, Mother and Crone as roles a person moves through in ritual rather than a fixed life-stage assignment.