Kent, the email I sent to the name found on new.familysearch was a dead end - the email came back as undeliverable - they probably have a new email address.
I did a google search on Sarah and found a small mention of her in a talk given by Dallin H. Oaks. The talk is found in the May 1987 Ensign, entitled Priesthood Blessings. Amazon.com books shows it out of print, with limited availability but no info as to where to find an out of print copy. I have purchased a few rare, out of print books for our middle son, who is an Institute Director for Penn State L.D.S. students. He has a large library of church books and I have found several out of print books for him in bookstores dealing with out of print church books, located in Salt Lake City. One is Weller Book Works and the other is Benchmark Books. I called Benchmark (they have an 800 number) and they do not have a copy. Weller Book also has an 800 number so I called them too, with no luck. I also have a list of personal family histories published by Stevenson Genealogy in Salt Lake (most of these are on CD's in their files) but I found nothing for Sarah Young Vance or anyone in her extended family who might have submitted copy to Stevenson Genealogy. I did call the public library here, and they will de a search for the book with all libraries thru the book title and author's name and they will answer my query within 24-48 hours. The Arizona Historical Society will be my last resource, but they are closed today and will be open tomorrow - I will let you know if they have anything written by Sarah.
From Dallin H. Oaks' talk:
"About a hundred years ago, Sarah Young Vance qualified as a midwife. Before she began serving the women of Arizona, a priesthood leader blessed her that she would "always do only what was right and what was best for the welfare of her patients." Over a period of forty-five years Sarah delivered approximately fifteen hundred babies without the loss of a single mother or child. "Whenever I came up against a difficult problem," she recalled, "something always seemed to inspire me and somehow I would know what was the right thing to do" (L. J. Arrington and S. A. Madsen, Sunbonnet Sisters: True Stories of Mormon Women and Frontier Life, Salt Lake City: Bookcraft, 1984, p. 105).