You can limit your search to e-books, but if you find books that are only in print, but could really help you in your research, here are some options to try:
Many public and special collection libraries and historical societies will have non-digitized files on people, places, events, and etc. within their holdings. Make sure to reach out to them for more information about individuals and any specifics on finding additional resources in the local area.
The Indiana Historical Society and the Indiana State Library has a rich collection of women's history materials. The Indiana Historical Society has made a comprehensive guide of their women's history materials on their website. The Indiana State Library houses the records of many women's organizations. A filtered search of those collections can be found via their Manuscript Catalog. Both institutions continue to digitize their collections via the Indiana Historical Society Digital Repository and the Indiana State Library Digital Collections.