The book is out of print. I was able to find a second-hand copy from 1993, with a cheesy cover. It's quite short, not even 50 pages, but it is incredibly interesting to anyone interested in the Little House universe.
It gives a brief account of Eliza Jane Wilder's life, but the most important aspect of this book is the publication of her own manuscript of her experience as a single woman homesteader in 1880s Dakota. Eliza Jane was Almanzo Wilder's sister and Laura Ingalls Wilder's sister-in-law. She is famous in the Little House series for teaching in DeSmet when Laura herself was at school, and she isn't the most likable character.
Through Wilder in the West, we see a totally different Eliza Jane - Eliza Jane and Laura purportedly didn't get on too well, and the Little House books are romanticised memories. Eliza Jane was a bit of a badass woman, if you'll excuse my language. So, even if one isn't necessarily a Laura fan, it would still be an interesting read for anyone wanting to learn more about strong women.