Virginia Reed Murphy was twelve/thirteen years old when her family became one of the central groups of the Donner Party. This recollection was written decades later, with lots of hindsight to inform the story. So, while her opinion and stance has been colored, and the references to cannibalism are reduced to about one sentence(and, considering the time period and her own personal experiences, who can really fault that edit?), it's still a very good introduction to the Donner Party's experience.
The story is more of a broad outline than a blow-by-blow account. Interspersed with Virginia's memories are contemporary diaries and letters kept by Patrick Breen and Virginia's father, James Frazier Reed.
But there's real emotion in here as well. The voyeuristic outside world may want to hear more about cannibalism, but there is far more to the story than gruesome bits and pieces. It was an epic struggle to travel west under the best of circumstances...and there were plenty of NOT best of circumstances facing this crew.
Virginia watched her father murder a man. She and her family abandoned everything they owned. She watched her mother struggle to keep them all alive. She herself almost died -- saved only by the charity of others in the group. She had to leave behind her brother and sister. Basically, as a middle schooler, she'd already seen and felt more danger than most of us will confront in a whole lifetime.
That's worth reading about.