Honestly though if she's reading on her own she's probably old enough for you to read it verbatim and explain the racist concepts and why they aren't acceptable/would have been put in the book. She's going to run into these concepts at school, better that she understands what is/isn't acceptable, and why, when she does. Of course, bed time, while reading a chapter of the book, may not be the most convenient time for that.
That's pretty much where I am. We always try to answer her honestly and explain things, but I don't really want to get into a discussion about race and the evolution of language over the last half century while she's falling asleep.
I do point out frequently that CS Lewis was closeted gay racist and tell her that all Christians are that way, of course. I mean there's always time for SOME lessons.
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