Earlier, I touted how Back to the Future was pretty much a perfect series of movies that remarkably still holds up well thirty years later. That is, if you overlook the elephant in the timestream - the disturbing lack of usage for Jennifer, Marty's girlfriend.
At the end of the first movie, she's brought along for the time machine for purposes not yet revealed, and then unceremoniously "drugged" and dumped into a back alley (instead of the car) at the behest of Doc Brown who despite his urgent urging, never puts her to use. Much like the problematic plan of inducing near-rape to convince Marty's parents to get together, the implications of which are lightly touched on, and underplayed (what WAS going through Robert Zemeckis' head when he wrote that down?) for a movie whose themes basically touch upon incest.
There's plenty more at the link, including how Jennifer's basic function is to serve as a catalyst for further time-travelling between Marty & Doc, and how she's dumped (again!) in the bad present without bothering to check to see if she's alright.
Usually, the role of women in these time-travel movies is regulated to being little more than bystanders or eye candy, not unlike The Time Traveller's Wife. (A somewhat romantic book that had creepy overtones of a girl stalked throughout her growing life by an older man, who in turn would stalk said man as her future husband, because it was destiny or something) More observers than participants, with rare exceptions such as Sideways (more like parallel universes) or Hindsight. Even with Continuum, a dystopian futuristic cop coming back in time (to our present) the timeframe where females can go is also similarly limited. It's been suggested that the overall reason for women being unable to travel through time is because of PMS. This is half of realistic expectations and half of failure of imagination. One the one hand, there's the illusion of keeping up appearances (See how much accuracy is needed for surviving without shaving implements, hair supplies or teeth-cleaning products) and the lack of urgency from working in short time frames. There's no absolute necessity for having to stay in the past for months or years at a time. On the other hand, there's the danger of knowing too much about what the future holds. Even if futuristic people have access to impressive fountains of knowledge, that access is useless if the populace is unwilling or unable to accept such blasphemous ideas coming from total strangers; let alone FEMALE strangers spouting illogical quandaries at them in an unknown accent.
One possible workaround is that if being a woman back then is extremely problematic, then just employ the tactic commonly used in gaining access to Female-allergic/resistant areas - pretend that you're a man. (Think Mulan or Michael Critchon's Timeline)
This was evident in the Gender-bender Manga, Kaze Hikaru, a Shojo Manga about a girl who joined the Shinsengumi for revenge. The first cover which had the perplexing colouring choice of having the top of her shaved head blue. (While still leaving her bangs visible)
Chances are, the extent of your familiarity with the Shinsengumi comes from Ruronin Kenshin, or more specifically, the closing montages of the Trust & Betrayal OAV where we saw a brief cameo of Officer Okita Soji (who never showed up in the series) who coughed up blood. This was a common staple of Okita, who suffered from tuberculosis and when some research was done, it was determined that it was impossible for him to have served his service while sick for so long, otherwise, his sword skill wouldn't have been so heavily praised. So an alternate explanation was given where the blood came from the target (and just happened to spill upon his shirt) so when he came down with tuberculosis later, history figured it must've occurred back then.
The author, Taeko Watanabe, is something of a history buff, and is notorious for doing investigative research, even while the threat of an approaching deadline's breathing down her neck. The behind-the-scenes production notes were some of the most popular pages of Kaze Hikaru, some readers vastly preferring them to the main storylines. (Not unlike the amusing bonus pages for Full Metal Alchemist) One of these focused on the problematic process of finding a plausible reason for her protagonist to stay for months without arousing suspicion among the majority of the members who didn't know her secret.
It turns out that much like the untold history of toilet paper, the secret of retaining periods was kept via oral history, which wasn't written down for posterity.
Even with pumping the elderly for information, the author didn't seem able to get anywhere. However, she was in Japan. And Japan has respect for certain female workers doing the world's oldest profession...
However, even knowing where to look didn't help matters any. There was information on the technique, but not how it looked or was designed. Research can only go so far.
It was only by chance while browsing another unrelated book that the author finally found what she was looking for. So you can imagine how difficult it would be for male writers to even ENTERTAIN the possibility of working around creative obstacles of a monthly ritual they have no familiarity with.