There's always more that can be said about the particular phenomenon you're asking about - you may find an answer to a question about a text called, "We have always fought" that I wrote last year relevant:

There's a whole bunch to be said about this topic and funny enough, I spent part of yesterday listening to three women historians talk about different groups of women in history as we recorded a panel for the upcoming AskHistorians Digital Conference. While we didn't discuss warfare in particular, we did discuss historical conflict and the gist of your question as we were wrapping up our conversation. They, and others who study the history of conflict, likely have a lot to say and will hopefully chime in. I think, though, it's helpful to speak to a larger issue around the question you're asking. There's a lot going on in the essay you linked to but there's one particular line that's worth focusing on as its basically the heart of an answer to your question:

We didn’t see them.

As soon as I read that line, I was immediately reminded of one of the very best history books I've ever read, They Were Her Property: White Women as Slave Owners in the American South by Stephane E. Jones-Rogers. What makes Jones-Rogers' book so remarkable isn't her writing style - which is, to be sure, very good - but her topic, research, and conclusions. For generations, the prevailing sentiment among historians of antebellum America was that slavery was very much the work of white men; there was a sense that white women were akin to bystanders, or so disempowered by the institutional sexism of the era they were passive participants in the day-to-day operations of chattel slavery or legally barred from owning slaves. Or, if they did own slaves, if they were an enslaver, they were an anomaly. Jones-Roger opens her book by setting the context around why that was the case and one of the themes she touches upon was the historical practices of the historians doing the work. In effect, she offers that the historians who made up the historical consensus around chattel slavery until fairly recently looked for women in the places they looked for men. And when they didn't see female-coded names or explicit evidence of women, they concluded they weren't there. In effect, they didn't see them.

What Jones-Roger did instead was to look differently. She looked to other evidence and for the names and actions of white women who existed in the same places where chattel slavery did, who had economical ties to enslaved people. She looked to children's literature, women's social organizations, marriage contracts, wills, and most powerfully, the words of formerly enslaved people who gave first-person accounts as part of the WPA Slave Narrative project. She built on the work of historians of childhood, education, women's history, as well as the Atlantic Slave trade. It's not hyperbolic to say her work has profoundly changed the field's understanding of white women's role in chattel slavery in ways that will influence scholarship for years to come.

The lesson from Jones-Rogers isn't to affirm that women were dramatically under-countered in historical conflicts. Rather, it's to offer that as historiography expands, the nature of the "historical consensus" changes because the nature of who does history has changed. In other words, if you'd asked your questions 50 years ago, odds are good the historical consensus would have likely focused on "historical conflict" as war. 40 years ago, as women's history emerged as a field, the answer would have likely shifted as more women historians expanded our understanding of conflict and the impact of battles beyond the battlefield. Etc. etc. (As an aside, an example of this in education history has been a change in the historical consensus around Black education, led by Black Americans in the North, before and after The Civil War, as seen in the work of historians such as Jarvis Givens and Kabria Baumgartner. Basically, it was a lot more expansive and complicated than was previously thought.)

There's another line in the piece that I think is worth highlighting:

I had no idea what to say to this. I had been nurtured in the U.S. school system on a steady diet of the Great Men theory of history. History was full of Great Men.

It's worth cautioning against the trap of the Great Woman theory when it comes to women in historical conflicts. "Molly Pitcher" is a great example of what that trap can look like. Mary Ludwig Hays is often identified as the woman who fought at Battle of Monmouth in 1778 and her story is often framed as that of a camp woman who courageously took up her husband's position at a cannon when he was injured. There are markers for her at the Monmouth Battlefield and her presence is framed as a woman who bravely did something other women didn't - or couldn't - do. Historian Linda Grant DePauw however, starts her article, "Women in Combat: The Revolutionary War Experience" in a January 1981 edition of Armed Forces & Society by stating plainly:

During the American War for Independence tens of thousands of women were involved in active combat.

Grant DePauw would go on to establish the Minerva Journal of Women and War and published multiple pieces exploring how "Molly Pitcher" wasn't one woman, rather, the Revolutionary armies were teeming with women, and the moniker was used for some of them and for a variety of reasons, their histories were minimized or merged into one. (This is a great piece that gets into the history of "Molly Pitcher" as a historical figure.)

All of which is to say, to paraphrase one of the upcoming conference panelists, girls and women are 50% of the population. Wherever there are humans, there are going to be girls and women, and that includes places and times of warfare and conflict. Finally, the fantastic u/Snipahar pulled together a collection of AH answers about women in history here and several of the past and current mods who are women who study history provided context around the field and the profession here.