With thanks to the research of WW1 researcher Debbie Cameron, who has a page on Facebook commemorating the women of WW1 - https://www.facebook.com/groups/1468972083412699/
here is a Christmas poem written by a nurse at the end of the war. Helen Nightingale features in the anthology "Great Ward Poetry" edited by Simon McNeill-Ritchie (who has a Facebook Page for Great Ward Poetry).
We had an exchange of e-mails in October 2014 about Helen's nationality and with Debbie's help I think we can now say that Helen was British. More soon. In the meantime, here is Helen's Christmas 1918 poem: