The Gospel of Mary, like most of the apocryphal gospels, is much, much later than the canonical gospels. Most were written by gnostic sects, and were never seriously candidates for inclusion in the New Testament.
It's clear that many of Jesus's followers were women, and that he loved and respected the women in his life. In the encounter with the Canaanite/Samaritan women referred to by HeadinHands, for example, Jesus shows that he listens to the woman and changes his mind because of what she says. Women were the faithful with him as he died, and were the first witnesses to the resurrection. It is clear from Acts and the Pauline letters that women were extremely prominent in the early church. All the historical records show that from its earliest days Christianity was especially attractive to women, mostly because women had a much higher status in Christianity than they did in paganism.
So why were all the apostles male? Because Jesus was living in a strongly patriarchal society, a society in which women and children had very little status. Priests, scribes, landowners -- all were men, and only men. By valuing women in the way he did he hugely challenged the society he lived in. The naming of the 12 friends as 'apostles' and 'disciples' (these words don't have hebrew equivalents appearing in the Old Testament) may well have been done by the gospel writers, who were fitting in the probably much more complicated group of Jesus's close followers into a pattern that would be comprehensible to their readers.
12 tribes of Israel: 12 disciples; male priests and scribes: male apostles. But there is plenty of evidence that women played a large part in Jesus's ministry and in the early church.