She certainly knew.
Her biological mother was a female worker from a laundry factory who came from the countryside. Due to her good looks, she caught the eye of a big boss shortly after arriving in the city to work. Not long after, she became pregnant with the boss's child before marriage. But after she became pregnant, the man who had promised to marry her disappeared.
By then her belly was already quite big, and when she went to the hospital for a check-up, the hospital advised against abortion, saying it would harm her body, and that the child was growing very healthily. It would be a lovely child if born.
Her foolish mother was persuaded, and secretly gave birth to her without her family's knowledge.
