I get why you're asking but I think the question is back to front.
The response in the media and then the vigil was the outlier.
2-3 women are killed a week and we don't usually hear anything at all about most of them.
With Sarah everard she first was missing so there was an appeal for people who might have seen her. The media picked it up and reported on it a lot probably because she was white young good looking educated etc. There have been plenty of studies showing that certain types of people get more press attention than others.
Then after a few days, when the fact she was missing had been in mainstream news, they found her. The media interest and reporting continued.
I don't think speculating that Julia James has not had vigils etc because she is with the police etc is the right direction. Her death has been reported a lot in mainstream media and it would be wrong to think no one cares.
Most women don't get reported on at all.
The other point with Sarah everard which has been mentioned is the fact that a police officer was arrested. Turns out he had carried out a sex offence a few days before which had massive escalation sex offender written all over it. I have lived in met areas for more than 40 years. They have a list of uselessness, arse covering and scandal as long as your arm. Warboys. Reid. Sapphire unit. Over and over they fail women and girls badly.
In the Sarah everard case a retired copper came on telly and said oh indecent exposure we're not really interested in that.
He exposed himself in a Macdonald's in front of multiple staff and customers. His car was parked outside. The police were called and the numberplate provided. I doubt they did anything more than file it. The boldness of that incident should have raised interest.
And then of course he turned out to be one of theirs.
Many women are angry. The Sarah everard media interest and then vigil were due to a mix of things but were very unusual.
Most women who are killed we never read about or see reported on the news.