A woman whose husband belonged to the artillery and who was then attached to a piece in the engagement, attended with her husband at the piece for the whole time. While in the act of reaching a cartridge and having one of her feet as far before the other as she could step, a cannon shot from the enemy passed directly between her legs without doing any other damage than carrying away all the lower part of her petticoat. Looking at it with apparent unconcern, she observed that it was lucky It did not pass a little higher, for in that case it might have carried away something else, and continued her occupation.
Joseph Plumb Martin
In short--a woman, whose husband was a member of the artillery crew, took a position on the crew during the Battle of Monmouth. The reason for this is most likely that she was in the vicinity--running water, bringing supplies--when a crew member fell to enemy fire or became ill with heatstroke (as a sidenote, at least 50 British regulars died of heatstroke at the Battle of Monmouth--it was hot). It is also possible that she was standing between the person loading the gun and the person running cannon rounds, making the trip more efficient.
Second, when it became necessary, Molly stepped outside her "feminine" role and took up a position on the artillery piece. Why didn't the crew just pull a man to do the job? They probably preferred working with a woman who knew what she was doing--as a camp-follower member of the artillery, she would have been familiar with the drill in a way that an inexperienced infantryman would not have been. Pulling a green man would have slowed things down or, worse, caused an accident--cannons are dangerous pieces of equipment to work with. Perhaps, as a lark, the men even trained some of the women--after all, teaching is the best way to sharpen up your own skills:
A 1780 cartoon depicting such a lark--and I know the boys of our reenacting unit love to try to teach us the Manual of Arms. Emphasis on "try."
I'm not sure what she's supposed to be wearing (ye olde milkmaid costume?) but when the cannon she's lighting off recoils, she's going to be Flat Molly. No account of Molly Pitcher indicates that she fired the piece, by the way. But perhaps an unrecorded "Molly" did...
Before we sign off on Molly, let's take a look at the varied (hilarious) artwork depicting Ms. Pitcher in action:
Molly with Shirtless Guy. And a very cluttered field--you kids need to clean up this mess or no hardtack, do you hear me?
Puritan-Costume Molly with Gun Pointed at Ground. Or downhill--better move that wounded guy or he's going to be in bigger trouble if that thing rolls downhill.
Tomorrow...Cross-Dressing for a Cause...