Tia Dalma has also another type of identity, which involves her being the sea goddess Calypso. This was before the Brethrem court of the Lord Pirates imprisoned her into a human form. She was also Davy Jones's lover
During her human form, Tia Dalma didn't know about the crucial role that Davy Jones had played in her imprisonment.
Tia Dalma is seen at the end of the first story in a cutscene which she is seen taking Hector Barbossa's dead body out of th Isla de Muerte's cave. Then at the ending of the second story she then resurrects Barbossa to help the crew of the Black Pearl get Sparrow out of Davy Jones Locker.