I never understood that. It seemed like Kirk's girlfriend had to have a boyfriend. She tells Kirk if he wants to leave her, she's got someone lined up a a stopgap boyfriend, but then she needs to be transferred to another ship to hunt fresh game. She also says she works in a chem lab. Does she make no effort to advance in that capacity, i.e. by making poison or explosives or just by being a reliable chemist for whoever the top dog is? Does all her career advancement come from her boyfriends? Maybe it's both. Maybe people do advance by doing their job, but on the side women have boyfriends and men commit murders.
The sexism of it doesn't bother me because it's supposed it's the mirror universe where people are bad. But I was very unclear how the sluttiness fits in. What do people do when they're 50 y/o, still fully capable of doing an intellectual job like chemistry, still able to fight, but past the age of having a lot of boyfriends and girlfriends? Do they take to mother and grandmother roles, where they're supposedly honored for traditional roles maintaining the home? Maybe their goal is to get pregnant by some high-ranking person.
My point in this depressing line of thinking is that I understood how the men desired to seize power through violence, but I don't understand what Kirk's girlfriend was after.
Wut, 50-somethings can't have lots of fun flings (and/or things potentially related to that, which may not be as fun - not as often a handful of shiny new babies, but instead various forms of shiny new itchy cooties...)?
Otherwise, yeah, what would Marlena want? She knew of the special control panel installed ("Tantalus", nice tie-in too...) where she - at the Captain's behest, it seems - can bleep anyone out of existence (until the plot demands she stops at just the right moment even though it's still the evil counterpart, which doesn't affect the primary universe's equivalent - but Evil Sulu was actually just as cool in his own ways and Marlena may have wanted him too, and he was salivating being next in command should Spock die, but I digress...) It'd make more sense for her to bide time, merrily pick off all the men, and eventually take over the ship and its worried crew then show the evil Slatfleet* that women could command ships just as effectively as the men folk? Or better since she wiped out a quaint number of them...

I vaguely recall she had full control of the device and no pre-authorization code was needed, which then begs a slew of fun questions should anyone wander into his cabin - especially afterward when he goes to the sonic shower... *cough* Yeah, I'm confused to as to where her subplot was really trying to go. Her to remain subordinate to any newcomer captain that is promoted? That would have some advantages too compared to outright power, I'd guess.
* yeah, it's a typo but was such a good one and fits in with their way-out universe that I thought it should stay

In real life and in our world, listen to the B-52s album "Funplex" if you can. The bandmembers were in their 50s (and 60s,
woohoo!) at the time, and just about every song on the album involves having various forms of copulation, foreplay, and/or picking someone up for such activities... I wonder if the funplex is on the way to Pierson's B-n-B with her S-U-V? ♪
♫ It's a great album,. Shame they didn't make any more after 2009...
And how would she necessitate a ship transfer when she has that power at her command when she can lallygag inside the captain's bedroom whenever she likes? If she leaves and the captain returns, does he quaintly zap her too? I know McCoy whined "What kind of people are
weeee?" then led into a song by "Information Society" known for using Star Trek dialogue samples, but little did he know how immensely whacked this mirror universe was.
But it's been forever since I saw this one, so a rewatch is in order...