There are several reasons why it is important to cite your sources:
WASM Entries Citation Tips
The Association for the Preservation of Historic Congressional Cemetery has a pamphlet titled Congressional Cemetery Walking Tour: Suffrage! (http://www.congressionalcemetery.org/pdf/Walking-Tours/Suffrage.pdf) that contains a brief biography of Winifred and shows the location of her grave in the cemetery (last accessed March 1, 2017). Additionally, there is an oral history transcript from and interview with Alice Paul that contains some biographical information about Winifred: Conversations with Alice Paul: Woman Suffrage and Equal Rights Amendment: Oral history Transcript, 1972-1976, University of California Berkeley, 1976. (Available on the Internet Archive) https://archive.org/stream/conversationsalice00paulrich/conversationsalice00paulrich_djvu.txt
If you need help with citations, please don't hesitate to ask a librarian or archivist or your instructor for assistance!