I'm not sure about this country but I have been surprised that when on European hikes, I have seen and met a few young women that were hiking alone. For what its worth (I write as a male here) I have wild camped a lot in the UK and to date I have never experienced a problem. I do not think this is solely because I am a bloke, I have always taken the view its because when I am wild camping I do not tend to pitch my tent until dusk and I make the effort to camp in discrete places. The type of person that people might worry about, the petty thief, the chancers, sex fiends and so on, I would suggest are most unlikely to make the effort to go to places where people like us would go.
Four years ago I once had a conversation and an en-route lunch with a young women from Herts who was going north on the Pennine Way, I was going south. She was slim, mid twenties and about 5' 2" and an accountant (I mention this because she kept talking about her job) and while we were eating it started to rain. Without moving away from me she suddenly took off her no-sleeves vest down to her bra, fumbled around in her rucksack for a long sleeved one and then put it on. She then whilst talking, she just dropped her shorts down to her briefs and fumbled again in her rucksack to bring out a long pair of trousers and put them on. She had no concern about me sitting there at all!
I must admit the experience scared me and I told her so! She just laughed and said she doesn't worry about men on hiking trails, they are always worn out anyway, so they would never try anything! I thought she was a fool and within 5 minutes I walked on, shaking my head and tutting!
Years ago a manager I worked with always said "Be discrete lad, be discrete", personally in wild camping terms its not bad advice.