A. Many records relating to individual war service from World War I are at the National Personnel Records Center (NPRC) in St. Louis, Mo. You can access information about the NPRC via the National Archives and Records Administration (NARA) website as this is a National Archives facility. Not all records survived a fire at NPRC in 1973. Plus, the records genealogists are accustomed to using for earlier wars aren’t as abundant for 20th-century wars. But published histories about WWI nurses and women in the military will be helpful resources.
Your inquiry didn’t mention which NARA facility you checked or with whom you spoke, but NARA does have many records related to World War I nurses. It will be important for you to determine if the person was actually in the Army or was a Red Cross nurse (learn more about Red Cross nurses here). You also need to know at what hospital(s) she served. NARA stores some records of military individuals in the hospital records, but they are organized by hospital and aren’t indexed by individual names. You might also do some reading in the helpful guide American Women and the U.S. Armed Forces: A Guide to the Records of Military Agencies in the National Archives Relating to American Women (National Archives Trust Fund Board). Once you find some records of interest, you should contact NARA to determine where the records are actually housed.