Hopefully the OP has no intention of going round to see this woman and her DH... but for those who have had the good fortune not to have come across people this loopy...
Do not do this.
It will be retold as 'HighFive and MrHighFive came to our house and attacked us/abused us/made threats to us'.
Then when people ask 'did you go to their house and...'
The honest answer is going to have to be 'yes' and the 'but we were polite and just asked them to leave us alone' part will be missed, glossed over, not heard, disregarded.
Similarly, letters, posts on social media etc, will all be twisted. Any approach instigated by Highfive and/or her DH will be embellished and fashioned into something else entirely and the grains of truth those tales are based on will give it further weight.
Don't speak to her, don't approach her, if she approaches you walk away, saying NOTHING at all, and keep on at the police. Be open if anyone asks you but keep it brief, it sounds like she is going to dig her own hole here so just let her.