It's become popular in many Protestant circles to say that we need to find a balance between Protestant and Roman Catholic views of Mary. Supposedly, Protestants, especially Evangelicals, are overly negative about her. In an attempt to resolve that alleged problem, we're often encouraged to give a lot of positive attention to Mary during the Christmas season. She's often featured in Protestant sermons, for example, as a model believer. Sometimes we're even told that Protestants have a problem with being "afraid of" Mary, being "suspicious of" her, etc.
But if Protestants have gone too far in holding a negative view of Mary, Catholics (and, to a lesser degree, Eastern Orthodox) have gone too far by a much larger degree in the opposite direction. Erring by a mile is a lot worse than erring by an inch. I would argue that Protestants, as a whole, aren't guilty of being overly negative about Mary at all. They're probably somewhat guilty of being too positive about her, largely because of misguided efforts like the ones I referred to in my first paragraph above. I suspect that the vast majority of Protestants know little about how much the Bible and other sources, such as the church fathers, say about issues like Mary's sins and her not being a perpetual virgin.
Another problem in Protestantism is the tendency to be shallow in sermons in general, including Christmas sermons, and to be overly repetitive in what's taught at Christmastime. Over and over, year after year and decade after decade, we get shallow sermons about Mary as a model believer, Joseph as a model believer, what we can learn from the magi, how the shepherds illustrate God's concern for the lowly in society, etc.
There's a solution to both of the problems I've mentioned above, and it would solve some other problems at the same time, but it's not often implemented. Preach (or teach a Sunday school class, for example) about how the Mary of Christmas differs from the Mary of Catholicism. If you go into significant depth about Luke 2:7, 2:35, 2:48-50, and other relevant passages, your congregation will be better informed about scripture, will mature in their exegetical skills, will know more about Mary, will have a more accurate view of her, will be better prepared to interact with Catholics and other people who hold an inaccurate view of her, will know more about Jesus' background, including the home he grew up in and the relatives he lived with, etc. It would be an improvement over the sermons we usually get during the Christmas season.
You can find a lot of material on the anti-Catholic nature of how Mary is portrayed in the Bible's Christmas passages in my post here. You can read the whole article or use the Ctrl F feature on your keyboard to find the most relevant parts of it. You can find more material by searching our archives, like this post that reviews a book about Mary by Tim Staples and this one that includes links to several posts addressing Marian issues. For example, the one here discusses Luke 2:48-50.