Who was actually Anarkali?

Anarkali was an Iranian slave girl who migrated to Pakistan and who lived around the late 1500's to the early 1600's. Her real name was either Nadira Begum or Sharf-un-Nissa. Traditionally, it is thought that she was buried alive between two walls by an emperor to punish her for having and illicit affair with a prince. However, there is no evidence that this story was true, so if it was, it was heavily embellished over time.