I was able to get my own copy, an old library book, from Preserving Christian Publications about 15 years ago. If you haven't read "At the End of the Santa Fe Trail" you are missing a profound glimpse into the history of the Old West, mainly Colorado and New Mexico.
It's not a novel or biography, it is simply her own humble journal that she was keeping to share with her sister. But, the life she lived serving the families of the settlers, the Indians and the cowboys was very dangerous. Her brave trust in God even led her to confront some Indian braves who were about to take revenge on some innocent settlers. Her description of the situation was so vivid that it still makes my heart race a little every time it comes to mind.