No, Ann is not Yang Dayong's daughter. Although they have deep feelings, it is only a father-daughter relationship between father and daughter. Yang Dayong once had a wife who loved Ann very much, but they broke up, so Ann is not Yang Dayong's daughter. However, An An is still Yang Dayong's baby granddaughter, and Yang Dayong has given An An great love. He always cares about An An's growth, and often buys all kinds of fun toys and books for An An to take care of An An's health and provide the best education for An An. The relationship between them is more like father and daughter, and Ann will take care of Yang Dayong. They live together like a warm family.