That out of the way, this is one of those book that has many different layers, takes place over the time of several decades, incorporates a ton of history and has many, many different characters.
Olive Wellwood is a famous writer, interviewed with her children gathered at her knee. For each, she writes a private book, bound in its own colour and placed on a shelf. In their rambling house near Romney Marsh the children play in a storybook world — but their lives, and those of their rich cousins and friends, are already inscribed with mystery. Each family carries its own secrets.
This summary does not even begin to tell what this book is about. I'm not feeling particularly deep at the moment, but I will be as thorough as I can.
At times I felt as though despite that hoard of characters that showed up in The Children's Book, this was not a character driven book. There were a few chapters that did not even include a single character. These chapters felt like they were taken out of a history book. It was great to learn about this era - the end of the Victorian era and Edwardian era - but sometimes I was just not in the mood. It felt like Byatt tried to cram as much history as she could. The characters themselves were used to show how the world was changing during this time. The great thing was that you saw the world through different perspectives: upper and lower class; male and female. The Children's Book mostly followed the children as they grew up, but also showed the lives of the adults, in a way so you could understand why the children ended up the way they did.
I didn't particularly have a favorite character because I felt, in a way, that all the characters were out of reach. We never really got to 'know' any of them. We saw them grow up, make bad decisions, fall victim to the times, and fight against society, but we were never able to get too close to them. Still, as events unfolded, I felt sorry for a number of them, particularly at the end, which takes place during WWI.
The Children's Book didn't strike me as wonderful or horrible; it's one of those books that, for me, hits somewhere in the middle.