The Woman of Revelation 12 cannot possibly be Mary

 People sometimes notice that the woman of Revelation 12 has a child who will rule the nation with a rod of iron, and from that they assume that the woman is Mary, since ruling the nations with a rod of iron is something ascribed to Christ.

However, the woman of Revelation 12 cannot possibly be Mary.  Revelation 12 is part of an extended vision that begins in Revelation 4.

Revelation 4:1-5 

1 After this I looked, and, behold, a door [was] opened in heaven: and the first voice which I heard [was] as it were of a trumpet talking with me; which said, Come up hither, and I will shew thee things which must be hereafter. 2 And immediately I was in the spirit: and, behold, a throne was set in heaven, and [one] sat on the throne. 3 And he that sat was to look upon like a jasper and a sardine stone: and [there was] a rainbow round about the throne, in sight like unto an emerald. 4 And round about the throne [were] four and twenty seats: and upon the seats I saw four and twenty elders sitting, clothed in white raiment; and they had on their heads crowns of gold. 5 And out of the throne proceeded lightnings and thunderings and voices: and [there were] seven lamps of fire burning before the throne, which are the seven Spirits of God.

The things which must be hereafter means things that are still future to John when John was prophesying these things.  Whether or not that is still future is outside the scope of this post.  

This vision contains a number of units, such as: 

• the book with the seven seals (Revelation 5:1-8:1)
• the sealing of the 144,000 (Revelation 7)
• the seven trumpets (Revelation 8:2-Revelation 11:15)
• the little book (Revelation 10)
• the two witnesses (Revelation 11:1-13)
• the three woes (Revelation 8:13-Revelation 12)
• the battle with the red dragon (Revelation 12) 
• the beast from the sea (Revelation 13:1-8)
• the beast from the earth (Revelation 13:11-18)
• the seven angels and their judgment (Revelation 14-18)
• the seven bowls of wrath (Revelation 15:1-Revelation 16)
• etc. (there are more, but hopefully you get the idea)

The woman is introduced at Revelation 12:1 at the beginning of the (sub-)vision of the battle with the red dragon, which itself is part of the third of the three woes.

 Revelation 8:13 introduces the three woes:

Revelation 8:13 And I beheld, and heard an angel flying through the midst of heaven, saying with a loud voice, Woe, woe, woe, to the inhabiters of the earth by reason of the other voices of the trumpet of the three angels, which are yet to sound!

Notice the connection between the three woes, and the three remaining trumpets of the three angels (out of the seven angels with seven trumpets), namely the fifth angel, the sixth angel, and the seventh angel.  

The Fifth angel sounds in Revelation 9:1.  Revelation 9:12 then says "One woe is past; and, behold, there come two woes more hereafter."  The Sixth angel sounds in Revelation 9:13. Revelation 11:14 then says "The second woe is past; and, behold the third woe cometh quickly."  That's when (in verse 15) the seventh angel sounds, and third woe begins.  In case you have any doubt that this is part of the same overall vision that began in Revelation 4, note the consistent imagery:

Revelation 11:15-16 

15 And the seventh angel sounded; and there were great voices in heaven, saying, The kingdoms of this world are become [the kingdoms] of our Lord, and of his Christ; and he shall reign for ever and ever. 16 And the four and twenty elders, which sat before God on their seats, fell upon their faces, and worshipped God,

Notice that the twenty-four elders around the throne are still there, although now they are no longer sitting, but have fallen on their faces to worship God. 

Revelation 11 ends at verse 19.  Revelation 12:1, thus, comes only six verses after Revelation 11:14 and the woe that was described as coming quickly.  Within the midst of the vision of the battle with the dragon is the explicit mention of "woe":

Revelation 12:12 Therefore rejoice, [ye] heavens, and ye that dwell in them. Woe to the inhabiters of the earth and of the sea! for the devil is come down unto you, having great wrath, because he knoweth that he hath but a short time.

The scene changes at Revelation 13:1, where John is no longer in heaven, but now by the sea.  So, we can only conclude that Revelation 12 is part of the account of the third woe associated with the seventh trumpet of the seventh angel.