Depends who 'owns' the fence. If your friend owns it then the neighbour can't demand any change to the type of fence, unless its too high. As to the position, we had this problem once. I smiled politely, acted the dizzy blonde, and suggested it was all beyond me and why didn't they chase it up and I'd fall in with their wishes. Of course they couldn't be bothered.
Found this a useful tactic in management too (not the dizzy blonde!) but saying 'good idea, put in it writing would you and cost it out' very few did.
Rather than get into a dispute why doesn't your friend smile vaguely ( and sweetly if she can manage that too), look confused and suggest they dig up their deeds, measuring tape, etc and look into it. She might also suggest if they want to alter the fence perhaps they go go halves as she's on a pension/budget, etc.
Hysteroscopy using spinal block/epidural
