What an interesting question! I would agree with your reply that just because something is newer or more modern doesn’t necessarily make it better. And I would be very hesitant to say that God gave us textbooks, or any book other than the Bible, for that matter.
In fact, when you think about the Bible, it is full of narratives, poetry, letters, and essay-type writings (the prophets). God gave His Word as the living Book. Imagine, for example, if God had given us the textbook version of the life of Christ or Acts. No, He gave us the narrative accounts, and Jesus shared so much of His teaching in parables and stories. But I’m off on a tangent . . .
I also agree with easybrizy about the arts. I’m reading a book that a friend recommended, The Element, that discusses how conventional schooling doesn’t recognize the different types of intelligence that God has placed within such a variety of people. Conventional schooling and testing has focused only on intelligence with math and words. But the Charlotte Mason approach gives value and appreciation for all those other types of intelligence that are expressed in creativity with different media. The book is not written by a Christian, but as I read I cannot help marveling at how God with His infinite creativity has put a glimmer of that creativity within each person.
So all that to say, I don’t have a great book or article suggestion for your friend, but I would caution her not to assume that newer equals better.