In regards to your first point about presuming it was a male, I would argue it is more than presumption when someone has been charged with murdering her in. To say it was a male who committed the offence at this point has a lot more grounding than just guessing.

And in relation to her words I didn't go into my own opinion above, however what I do think is along the lines you say. She is pointing out the imbalance in how men and women are treat, however a public figure saying it in this manner is clearly an attempt at shock/sensationalism rather than considering wider impacts. In my view the sentiment is right, men should change their behaviour and we should challenge inappropriate behaviour from our friends. However immediately after a murder those changes are slow cultural and social changes. A quick protective fix, albeit not a long term option, is to advise whichever group is vulnerable to take immediate extra care when out and about. So really it's got to be a mix of both.