Why was Wang Lung schocked at Olan's goals?

O-lan begins to show some thought for herself after the birth of her first child, and the way she asserts herself comes as a surprise to Wang Lung. Her adament refusal to accept help from the great House during her childbirth suggests that she was treated very badly during her time there, and she makes many preparations before showing her first-born child to the Old Mistress. Wang Lung, though he might not fully recognize her worth, represents an escape from the nightmarish slavery she experienced at the house. She seems to take pride in displaying her first-born swathed in fine clothes, and is sure to point out the many clues that the great House's fortunes have declined even as Wang Lung and she have thrived.