Mark mentions the names of the three women on three occasions (Mark 15:40, Mark 15:47; Mark 16:1). This is likely because they were witnesses of these events. They were the ones who told him that they watched Jesus crucifixion from a distance, saw him being buried by Joseph, and went to the tomb on the Sunday morning.
The fact that Mark mentions the testimony of women encourages us to know that his Gospel is a truthful account of Jesus’ life, death, and resurrection. If Mark or the disciples or anyone else for that matter wanted to make up a story about Jesus and convince everyone he had been raised, they would most certainly not have made mention of any kind of women witnesses. In the time of the New Testament, women were treated as second-class citizens. Women were considered unreliable witnesses in court; their opinions did not matter. To call on a women as a witness would be equivalent to us asking a child to give testimony.
And so the fact that Mark goes out of his way to mention these three women as witnesses is significant. There is no reason why he would mention them unless they really were the people who went to the tomb and saw the messenger. The presence of these women is a testimony to the authenticity of his Gospel. He didn’t just make up facts; he gave us an accurate account of what eyewitnesses told him
40 There were also women looking on from a distance, among whom were Mary Magdalene, and Mary the mother of James the younger and of Joses, and Salome.