I've been on a little bit of a 'women and war' kick recently because I've had some odd experiences in London with men who don't think that a woman should write a biography of a general. If women can fight wars and lead armies ... I figure I can write about them.
There are admittedly very few women who write about military matters - Margaret MacMillan, Caroline Finkel, Lyn MacDonald, Beatrice Heuser, Anna Maria Brudenell, Lynette Nusbacher.
The only person I can add - and I'm ashamed to admit that until this morning I had thought she was a man - is Pat Southern.
Her book on the Roman Army has been given a great review by BMCR (I have not read it yet, as it concentrates on the Imperial and Late Antique periods, not the Republic).
The Roman Army: A Social and Institutional History. OUP, 2007
Later this year Southern will publish a biography of Zenobia - which will be a book about a female general, by a female military historian.