WTF, thats insane!!!
Fair play to the boy for not doing anything, i'd have had to walk away after the first hit or i'd have kicked her teeth in, but i'd defo let my mrs deck her without intervening tho.
So whats the story behind it all then, all i could work out was a bin, something about a business and rates, and the boy being a gyppo....
As said above, just go to the cops, with evidence like that she can never even come near you or even talk to you, an assault conviction would just be the start.