I think that the idea of showing a lesser-known side to Sophie Scholl, that of her relationship with Fritz Hartnagel in the context of her evolution from childish support for Hitler to informed resistance as a grown-up, is very neat and one that would interest many other readers, as it did me.
But Alexandra Lehmann didn't handle this premise well. Historicity here is correct, for the most part, but the way the author presents Sophie and Fritz's story is terrible. The writing itself is bad enough, but is made even worse by the bad storytelling. There's an awkward presentation of the sequence of events, one thing happens and then another thing follows right after that without the first scene ending. Scenes are cut abruptly, like when you go from Sophie distributing leaflets at the Munich University to child Sophie having a "blood oath" ceremony with her girls' group and then abruptly throwing the reader into a town party one year later where she meets Hartnagel. The author simply has no idea of how to tell a story, she often leaves a scene mid-sentence, cannot write good dialogue, and leaves huge plotholes because she simply can't connect one event with the next or fill in the gaps that history left. The result is that the narration is one clunky and disjointed recitation of events in the correct timeline but told as if the writer wants to check boxes in a "this happened, then this happened too, and this other thing happened next" way. It's made the book frankly unreadable.
To make things worse, there seems to be an attempt to make up for the poor writing and storytelling by liberally splattering excerpts from Sophie and Fritz's surviving letters in-between scenes. Is this supposed to be a historical novel or a novelised biography? Whichever the intention was, this book doesn't succeed at either.
And as a final kick, at least for me, the author makes the same mistake as a gazillion other authors have: improper use of a foreign language. For the love of all that's holy, why can't authors just stop doing this? I am speaking, of course, of this stupid habit of having your character say a phrase in a foreign language, and then immediately make them say the same thing in English in the same sentence. How on Earth would Sophia Magdalena Scholl, a native German speaker, say something like "Kommen hier her, come here." when addressing a group of other native German speakers?! The ridiculousness of this never ceases to annoy.
I wouldn't recommend this novel, better to either read the original letters that survived and were published by Sophie's sister, or a better novel about the White Rose, like the one by Emily Ann Putzke.