From John 19:25 : "Now there stood by the cross of Jesus his mother, and his mother's sister, Mary the wife of Cleophas, and Mary Magdalene" Which seems to suggest that Mary had a sister, also named Mary. I've also heard arguments that Mary Salome was also Mary's sister which would suggest that there were 3 sisters all with the same first name.

What's going on time? Were they step-sisters? Is there evidence to suggest that this was a clerical error? Did one or both women change their names at some point in there lives? Was Mary used as a title similar to Caesar in Rome? Or was it common for multiple daughters living in 1st Century BC Israel to share the same first name?