Salome was the step-daughter of King Herod of Judaea, and she had been instrumental in the execution of John the Baptist.
What follows is conjecture, but there was a Salome who became a follower of Jesus.
When Salome met Jesus, she renounced evil and became one of his followers. She was there at his crucifixion and she was there when his body was found to have disappeared from the tomb and an angel approached her and Mary, and Magdalene, with the good news of his resurrection.