I was talking to a friend who writes crime, and is pretty knowledgeable about trends in the genre. In conversation it came up that the tactic of killing a random woman as a "pre-credits death" is somewhat frowned on these days, partly for reasons of feminism and partly because it's felt to be a bit old. However, I suspect that's more a thing in crime than SFF.
The thing is, in a murder mystery, someone is going to die, otherwise there is no murder to investigate. And it's going to either be a man or a woman, either cisgender or trans. Or even a none binary person. And to be honest, any person from one of those groups would almost certainly get an outcry of anger if they were killed off. As for when they get killed, it really depends on what suits the story best. Why did the killer choose this person?
I've no idea what the actual comparison is in fiction, how many men are murdered compared to how many women. A quick look online and the closest I could get was the real life stats for England and Wales in 2010/11 in a BBC article and it turned out nearly twice the number of men were murdered compared to women:
How unrealistic is murder on television?
Checking wikipedia it got worse again:
Homicide statistics by gender - Wikipedia with very few exceptions where real life female murders were greater than the number of male murders. It doesn't help that the stats are not for the same year.
As I can't find a comparison for the breakdown of murders by gender in murder mystery stories in general, I've no way to make any assumptions about the validity of any complaints about the "tactic". It's a perception that could be right, but might be wrong. I'd need to see a breakdown like that to judge for myself.
I have found one for Columbo, but he is strictly a TV character, but his total of male murder victims massively outweigh his total of female murder victims.
Over the course of its 69 outings, Columbo dished up an impressive 92 fatalities – that’s an average of 1.33 corpses per episode. But who died via which grisly methods? Read on and find…
columbophile.com
But the point is, anyone can be a murder victim, it's just in this case it's a young girl. I'm working on another sci and fantasy based murder mystery where the victim is a man whose murdered in the first chapter after he's spent a bit of time annoying people, including the detective.
I've an outline for another murder mystery that starts after the police find the body of the murdered man so we never get to know him at all.
And I'm putting together ideas for another murder mystery but have no idea who the victim will be, let alone their gender. That's something that I'll be deciding further down the line when I know what is needed for plot and character.
In any case, as it's a scifi/fantasy tale, there's twists coming you just can't get in a regular murder mystery.