The truth is messy, and that's a fact!
When writing Insane Inventors I wanted to let children know that scientists often take great risks in their research and creative process, and because of this people believed they were crazy. Alfred Nobel blew up his laboratory trying to invent dynamite. Lawrence Patrick was a human crash test dummy and broke nearly every bone in his body. And then there was Nikola Teslsa - brilliant and in love with pigeons. How much truth should I include?
I firmly believe that authors have an obligation to tell the truth about a subject, but I also believe that we can leave some facts for readers to investigate when they are older and better able to process information. Authors need to sift through the facts. Which ones are necessary to explain the story? Did children need to know that Nikola Tesla claimed to love a pigeon as he would a woman? I didn't believe that was necessary in a middle grade book. But I did tell them that he spent his final years living with pigeons. When they are older they can investigate further and draw their own conclusions. They will still be able to look back at my writing and know that I told them the truth.
It's a fine line. We need to be honest with readers and not cover up the more difficult parts of history, but we also need to be sensitive to the developmental age of our audience.