Read it through once

Oliver was surprised to see that as Mrs. Maylie said these words, she checked her lamentations as though by one effort; and drawing herself up as she spoke, became composed and firm. He was still more astonished to find that this firmness lasted; and that, under all the care and watching which ensued, Mrs. Maylie was ever ready and collected: performing all the duties which had devolved upon her, steadily, and, to all external appearances, even cheerfully. But he was young, and did not know what strong minds are capable of, under trying circumstances. How should he, when their possessors so seldom know themselves?