Queen Mary was born as a relative of the Royal Family, and her family had some financial issues, but they were, of course, improved once she was engaged to the future king. She was initially engaged to the eldest son of Edward VII, who was someone not very likeable. This prince died shortly after their engagement, and after the end of the mourning period, she was again engaged to the younger brother of her former fiancé, the future George V. Mary was fortunate in the sense that she and her husband were devoted to each other, quite unlike Edward VII and Queen Alexandra.
However, as parents, Mary and George were just like any parents in the Victorian upper class. They delegated the care-taking of their children to the nannies and governesses. When reading about the childhood of her children, I cannot help but feel sympathetic towards them because it does not seem easy to be the children of such parents. The problems Edward VIII and George VI had could be attributed in a large part to the childhood and teenage years they experienced. Edward VIII was a womaniser and someone without any sense of responsibility. He had so many mistresses, but never considered anyone suitable to be the future queen consort. He also had various curious contacts with the Nazis before the WWII, which was something difficult to understand. Ultimately, Britain and Germany had already been enemies during the WWI. George VI had a weak and reserved character, and he was just so fortunate to have Queen Elizabeth by his side. It seems to me that the author had written too much about Edward VIII. The parts of the book mentioning him and his various women were just so hard to read.
Queen Mary married into the Royal Family during the reign of Victoria, so perhaps it is no surprise that she was someone with very traditional values. Sometimes, this adherence to tradition can seem self-entitled from a modern reader's perspective. It is mentioned by the author that when she visited an aristocratic house and saw some antiques or artworks that previously belonged to the Royal Collection, she would simply ask the host to return these objects to the Royal Collection. Indeed, it was just so impolite and inconsiderate to do so.
In summary, Queen Mary was a complex figure. She was born in the reign of Victoria and died just before the coronation of Elizabeth II. She experienced two world wars, the downfalls of many European monarchies, and the change of the family name to 'Windsor' because of these upheavals. She was partly responsible for the recklessness of her eldest son, but she remained dutiful and steadfast in the face of wars and crises.
This book was relatively well-written, but it can become quite boring because it contains too many unnecessary details at times. The author held high regard for Queen Mary and the Royal Family, and so, as expected, she wrote many good things about them and avoided any reflections on the legacies of the British Empire.