My grandmother wrote an autobiography about 25 years ago in a spiral bound notebook, she has since passed away. While I am using mostly primary sources in immediate family members biographies such as her husband and parents, this work helps to fill out the biography a little more. It does not have a title. I have typed it into an electronic document, done some editing to the spelling and grammar but not changed any of her facts. One day I will probably self-publish it for the family. For now what is the best way to source it? Below is what I currently use:
Clark, Helen Harriet Whitney. Personal Recollections, autobiographical accounts written but never published, held in family archives.
You can submit the unpublished document to the Internet Archive (archive.org). Most documents there were submitted by libraries or large institutions, but anyone can create a free account and upload a document. Their mission is the archival preservation of documents available to everyone.
When you are done, you can link to the document from your Wiki Tree reference. Congratulations, your document has just gone from impossibly obscure, to easy for anyone to find and read for themselves.