Wow - I have followed all your threads. This woman sounds very similar to a woman who turned full on stalker towards me some years back. Each incident/encounter/message on its own sounds almost silly and like nothing... but when you put it all together it creates a pattern of rather worrying behaviour.
You are right to insist on her saying anything in front of witnesses. My stalker always had to deal with witnesses until one time she thought she was outwith earshot of others (she didn't realise that my friend was standing behind her). At that moment when she thought it was just me and her, she issued me a very chilling and sinister threat - no screaming, no shouting - very quiet, cold and calculated. So yes - always make sure you have witnesses. I'm not saying this to be dramatic or scare you - but just because I understand how something like this can sound so silly to people not involved... but you know there is something more unpleasant going on. Most instances of stalking/harassment start out as "nothing". Mine did - I was shocked at how easily the situation escalated into full on scary stalking before I even realised how serious it had become. It went from moments where I just thought "she has issues!" and not taking it very seriously... to the police being involved etc.
With my stalker we ended up at court and a restraining order was issued - but this was after months of continuous harassment and even her following me around in her car. When I got to know her car, she would hire cars so that I didn't recognise them. It was a very unpleasant experience.
I'm glad you have support from friends - just keep a note of things and as I say, make sure that any dialogue happens with witnesses about.
Finally - I know people have been saying to block her. While in some cases this is the best thing to do, it's not always best. By all means, do not respond to her - you have made it perfectly clear now, in no uncertain terms, that you want her to leave you alone. That is important with a stalker - to be able to show that you have made it clear that you want them to back off and leave you be. But with someone like this, it can almost be better to know if she's trying to contact you - you can see any escalation in behaviour (which might act as a warning to her turning up somewhere or whatever), patterns, and use messages etc... as evidence if it comes to it. So if it were me, I wouldn't block at this point but just keep any messages.
I hope she backs off and it all settles down, although having experienced this kind of harassment myself from someone who sounds eerily similar, I suspect she won't be going away easily.
Just carry on - remain as calm as you can - repeat until you are sick of it "leave me alone" - walk away. The more she pursues you the more she effectively proves that SHE is the one with the problem and it sounds like the less you engage with her the more determined she is becoming. Just be careful and if you at any point feel in danger, DO report it; people throw around the word "stalking" very lightly these days, but the reality of it is far from nice and this woman sounds like she is starting to stray down that road.
I hope things settle down for you. xx