Hi Tarquin,
Children can be such total brats - I really feel for your friend, 14 year olds are not exactly kids and I'm sure she must be feeling a bit intimidated by the name calling. She's really doing the only thing she can do - ignoring them as much as she can. I take it she's living on her own?
We moved into a house a few months ago and the next door neighbours seem to have quite a few children although there's generally so many people (adults and children) in and out of their house, it's hard to tell which children are theirs! They're in and out of our front garden from time to time when their ball has come over and as the house was empty for a while I reckon they got used to coming into the front garden whenver they wanted to. At first it was really annoying, even though they weren't half as bad as your friend's neighbours children, but I've grown used to it which is what my BF told me to do - they're not doing any harm (thank God) and it's just what happens in estates like you say. The next door neighbours friends also park right in front of our drive which I have to say, I am gobsmacked at. I would never dream of blocking somebody's drive but I suppose we always know who it is so if we need them to move it, we know where to go.
I hope she doesn't end up moving out, given that she seems to enjoy every other aspect of where she's bought.
M