OP, when I first read your post I had an image of the lady in question wearing a pair of roller skates and some sexy lingerie, clinging on to your bumper with wild eyes and a determined (toothless) grimace like a cross between a lunatic stunt woman / pornstar / old hag
Gave me a giggle but I must apologise - having re-read it he whole thing sounds bloody terrifying!!
Had to let you know my initial crazy thoughts haha but in all seriousness I'm really glad you are unharmed and weren't robbed.. And glad the WG didn't do herself an injury too, for both your sakes. What a bizarre, absurdly stupid thing to do on het part. I wonder what she was thinking at the time? I know, if I cling on to his car he will
definitely either pay up or present the perfect opportunity for me to nick his wallet..
Her pimp wouldn't have been much help, miles down the road!
In all seriousness though, she is clearly a dangerously WG to be avoided at all costs (to be honest I'm hoping I don't meet her in the street!) - it also sounds like she had some pretty bad mental health issues too, or is doing waaaay too much crack.. Telling the police could actually end up being the best thing for her if it means she gets some help with her "issues" but its probably pointless and definitely not your responsibility.
If I were you I would definitely get a PAYG phone NOT registered in your name, and find yourself a less unhinged lady as has been suggested
Onwards and upwards, lets face it you can't really go downhill from here!