Niobe
Niobe was the daughter of Tantalus. Like her brother Pelops, she is unusual in the House of Atreus for having failed to commit child murder, incest, or cannibalism. Her only offense was pride and arrogance, rather like her father.
Niobe had fourteen children, seven sons and seven daughters, of whom she was inordinately proud. She made the mistake of comparing the goddess Leto disparagingly with herself, as Leto had only two children, Apollo and Artemis, and she had her own brood. Unfortunately for her, two gods easily outnumber fourteen human beings, and Apollo and Artemis avenged their mother's honor by slaughtering the whole family.
Niobe's husband committed suicide in his grief, and Niobe mourned and wept until Zeus took pity on her and turned her into a rock from which a spring trickles eternally.