Who was turned into an unfeeling rock after bragging about her 14 kids?

In Greek mythology, Niobe was turned into an unfeeling rock after boasting about her 14 children—seven sons and seven daughters—comparing herself to the goddess Leto, who had only two children, Apollo and Artemis. As punishment for her hubris, Leto's children killed all of Niobe's offspring. Stricken with grief, Niobe was transformed into stone, forever weeping for her lost children.