Who was the girl turned into a bear by Artemis?

Callisto. Callisto was one of Artemis' virgin followers. However, she was raped by Zeus disguised as Artemis. When Artemis discovered that Callisto was pregnant, she cast her out of her Hunt. After giving birth, she was turned into a bear by Artemis or Hera or maybe even a calibration of the two. One account says that Hera turned her into a bear and sent her in Artemis' path. Before Artemis killed the bear, Zeus made her a constellation. Another says that she was made a constellation before her son could kill her.