The book...

...by von Balthasar that I mentioned (see below) was actually produced jointly bewteen Von B. and Joseph Cardinal Ratzinger, now BXVI. They sort of have it half-each. It's Mary - the Church at the source and it's fascinating. Explains just why the decision of the Fathers at Vatican II to include Mary in the document on the Church rather than just have something separate about her was hugely prophetic as well as being absolutely right.