Only you can truly decide what books are appropriate for your children. Check out reviews of books on places like Amazon and Common Sense Media or talk to other moms/dads before making your decisions. These are lists of books I have used or will use in the future. Books are listed by time period then by grade. E means k-5, M means 6-8, H means 9-12 HG means gifted high school or more complex than average high school reading or deals with more adult themes.
MIDDLE AGES and RENAISSANCE
A Distant Mirror: The Calamitous 14th Century by Barbara Tuchman H
A Journal of the Plague Year by Daniel Deofoe H
Eleanor of Aquitaine and the Four Kings by Amy Kelly H
A Summa of the Summa: The Essential Philosophical Passages of St. Thomas Aquinas’s Summa Theologica by Thomas Aquinas H