If we were to start digging into the demographics, then the typical white middle class mumsnet feminist who harps on about female murders would have to acknowledge that they themselves are probably not in the demographic that need to be most concerned (although tbf I'm not concerned myself given that well over 99.9% of women don't get murdered).
If you accuse women of 'harping on about female murders' then you need to accept that you sound like a misogynist even if you don't think you are one because you're a woman.
Men are more likely than women to be murdered.
Men are more likely than women to be a murderer.
When it comes to murder, the number of female victims is hugely disproportionate to the number of female perpetrators.
And two women a week are murdered specifically by male current or former partners. Men and women are roughly 50/50 of the population. Two men a week aren't murdered by their female current or former partners, so there's a colossal disparity that is disproportionate and specific to males harming females.
Wanting to raise awareness of that and campaign for change isnt 'harping on', it's essential for that change to happen.
The rate is the same even with the campaigning done to date and the DV provisions in place to try and reduce the rate, with the aim of course being to eradicate it. Imagine what the rate would be if no women had been 'harping on' about it and fighting for change within the community, by supporting women's rights charities and pushing for reform at a governmental level.
I bet you've never used the phrase 'harping on' about people of colour fighting agains racist murders.