Doraemon Is in My Pocket at the End of the Natural Disaster

[Non-rebirth (please enter with caution) + no cp + pure natural disaster + no hoarding + strong female] The heroine Qin Youyou picked up a pocket watch by chance and discovered that the pocket watch was a space that could conjure anything she wanted. However, what she did not expect was that the arrival of the pocket watch would be accompanied by the end of the world. While everyone was destroying humanity for the sake of materials, she relied on the infinite space to lead her sister to live a happy life in the last days. After facing the departure of her closest loved ones and the betrayal of her relatives, for the sake of the righteousness of her family and country, she did her best to help mankind rebuild their homeland. At a critical moment of life and death, she finally discovered the secret of space. From then on, she truly embarked on the path of the savior. . . .