Which sentence in Bing Xin's Paper Boat reveals the center of the article? Summarize its center in a short sentence.

This is your beloved daughter, with tears in her eyes./Wan Shui Qian Shan, please let her go home with love and sorrow. "Deep yearning for mother may be yearning for the outside world. Maybe it's longing for friendship and recognition, maybe it's bringing blessings to people far away, or maybe it's praying that the boat of her life can sail safely through the stormy waves.