Earlier this week, I posted an article on the perpetual virginity of Mary in response to the claims made by Philip Blosser in his reply to Steve Hays. In addition to his claims about the perpetual virginity of Mary, Blosser refers to other Marian doctrines in the church fathers. For example, he claims that Augustine "clearly argues for the sinlessness of Mary" (as quoted on p. 126 in Steve's reply to Blosser). Readers may be interested in articles I've written on the sinlessness of Mary here and here. Augustine is among the sources I address. Regarding the Assumption of Mary, see here and here. On the subject of the woman of Revelation 12, see here. Regarding prayers to Mary and Mary's status in Heaven, see here. On venerating images of Mary, see here.
Also worth noting is that many of the individual themes and Biblical passages that Roman Catholics apply to Mary aren't applied in that manner by the earliest patristic sources. For example, while Roman Catholics often see the queen of Psalm 45 as Mary, Justin Martyr refers to the queen as the church (Dialogue With Trypho, 63). So does Clement of Alexandria (cited in Eric Osborn, Clement Of Alexandria [New York: Cambridge University Press, 2008], 214). Roman Catholics often parallel Mary to the ark of the covenant, but the earliest ark parallels among the church fathers identify Jesus or something else, not Mary, as the parallel to the ark (Irenaeus, Fragments From The Lost Writings Of Irenaeus, 48; Clement of Alexandria, The Stromata, 5:6; Tertullian, The Chaplet, 9; Hippolytus, On Daniel, 2:6; etc.). Catholics often cite Revelation 11:19 as a reference to Mary's bodily assumption, whereas the earliest patristic interpreter of the passage doesn't even see Mary as the ark (Victorinus, Commentary On The Apocalypse Of The Blessed John, 11:19).
Catholics often respond by arguing that the fathers might have believed that these passages refer to Mary, even though they don't say so in their writings. That's possible, but how likely is it? For example, if so many ante-Nicene fathers comment on the ark of the covenant, and none of them draw the parallels that modern Catholics are drawing, how likely is it that they held the modern Catholic view, but just happened to repeatedly mention some other interpretation instead? As these fathers show us, we can make sense of these passages of scripture without appealing to a Marian interpretation. Why, then, should we think that some additional Marian interpretation is appropriate?