The goddess who repaired the sky after Gong Gong damaged it was Nüwa.
Nüwa is a mother goddess, culture hero, and creator figure in Chinese mythology. In the best-known version of the repair myth, the water deity Gong Gong damaged Mount Buzhou, one of the supports of the heavens, after a destructive conflict. The sky cracked or tilted, causing floods and disorder that threatened humanity.
Nüwa responded by melting or refining five-colored stones and using them to mend the breach in the sky. In related versions, she cut off the legs of the giant sea turtle Ao and used them as replacement supports. She also defeated or restrained destructive forces, including the black dragon associated with the floods. The story explains why celestial bodies and rivers were believed to follow particular directions.
Nüwa is also famous for creating human beings from yellow clay or mud, sometimes shaping them individually and sometimes creating large groups more quickly. She is frequently paired with Fuxi, who is portrayed in later traditions as her brother and husband. Mazu is a sea goddess, Chang’e is associated with the Moon, and Xihe is linked with the sun, so none is the standard answer to this sky-mending episode.