I don't interpret scripture. I let scripture do that. If you think the sign in Revelation 12 is Mary then you run into problems with Old Testament prophesy.
You can start with Genesis 37 where the stars bow down. Throughout scripture Israel is spoken of as a woman who will bring forth a man child. Isaiah 54. Isaiah 66 says Zion travailed and gave birth to a man child. The woman in Revelation 12 is Israel.
Riiight, and by what authority do you believe you can make this claim? Your own word?
Or wait, let me guess you're going to say something like "Not by my own authority but the Word of God as Scripture says...", in other words a circular argument.