Complex sentence: Though she was born into an enviable degree of middle-class comfort, the family's security was severely shaken after the suicide of her paternal grandfather, James Cartland, a financier, who shot himself in the wake of bankruptcy.
Split into simpler sentences: Though she was born into an enviable degree of middle-class comfort, the Cartland family's finances evidently had evidently deteriorated around the time of her birth. Cartland would later attribute this downturn to the suicide of her paternal grandfather, James Cartland, whom she claimed was a financier who shot himself in the wake of bankruptcy.