Traditionally militia has been regarded as an activity for men, but throughout history women have been involved as well, if not as among those required by law to respond to musters, then as among those who respond anyway, and having done so, play critical roles.
In the American Revolution:
Will the Real Molly Pitcher Please Stand Up?, © 1999 by Emily J. Teipe. Article about many of the heroines of the American Revolution.
"The proportion of Women which ought to be allowed...": An Overview of Continental Army Female Camp Followers, John U. Rees, Published in The Continental Soldier (Journal of the Continental Line), vol. VIII, no. 3 (Spring 1995), 51-58. The term "camp followers" has acquired a derogatory connotation, but these were militia who served a critical role.
Women Soldiers in the American Revolutionary War. In the beginning of the America we know there was a Revolution. And although the call to arms was for men, several women donned the uniform of a Revolutionary soldier and fought against the British.
Prominent warrior women in history (Wikipedia):