When Nathalie is interviewed about how being adopted effected her life, although initially she denies that it made any difference to her, she suddenly discovers a need to find her birth parents, and insists that her brother David (also adopted) do the same. This takes them down a road that neither of them were ever prepared to travel, and yet, are both, inexplicably drawn towards.
With "Brother and Sister" Joanna Trollope gives us a parallel study in human nature, but she does so with such simple artistry that you'll find yourself compelled to read this straight through. You can read my full review here. https://tcl-bookreviews.com/2013/11/09/adopted-siblings-road-to-discovery/