He was preoccupied with his work on his mother's portrait, which was taking a very happy turn; and often, when he sat silent, with his hands in his pockets, his legs outstretched, his head thrown back, and his eyes on vacancy, it was to be supposed that his fancy was hovering about the half- shaped image in his studio, exquisite even in its immaturity. "Roderick Hudson" by Henry James

Her figure, though slight with the slenderness of immaturity, was built on the right lines, and her young, eager face, in its frame of raven hair, was as vivid as a flower- its clear pallor serving but to emphasise the beauty of the straight, dark brows and of the scarlet mouth with its ridiculously short upper- lip. "The Splendid Folly" by Margaret Pedler

Without considering my motherless condition, my helplessness, the immaturity of my mind, he drew me day by day into the secret meshes of his great scheme, a scheme which, as I failed to understand till it had absorbed me, meant the unequivocal devotion of my whole life to the exclusion of every other hope or purpose. "The Chief Legatee" by Anna Katharine Green