The best, most detailed Catholic commentary on St. John's Apocalypse is
cf. the briefer, older commentary: The Apocalypse of St. John (1921) by Fr. E. Sylvester Berry
Commenting on Apoc. 12:1
("woman clothed with the sun"… etc.), Fr. Kramer writes:
The woman of chapter twelve is not the Blessed Virgin Mary.
According to the ancient Fathers, the human nature or character of the Church is here delineated, while in chapters four and five her divine nature and prerogatives were depicted.
The twelve stars represent the twelve apostles; or they may be God's mystical number symbolizing the Christian nations, that as a contrast to the ten crowned horns of the beast, shall be the glory of the Church when the days of Antichrist approach.
The moon under her feet has ever been understood to symbolize the unchanging and unchangeable character of the Church.
cf. these excerpts of his commentary on Apoc. 12
Also, St. John's Apocalypse
contains a detailed description of the Catholic Mass