And your solicitor will write saying "B ! off !", but in rather more forensic and diplomatic terms. My guess is that the other side will make a tactical withdrawal and no more will be heard. The neighbour being a solicitor they will, almost certainly, consult with colleagues and be tactfully persuaded to keep the peace between neighbours. This neighbour thinks that your mother, being quite old and not in the best of health, will be a pushover but is in for a change of opinion; not a great surprise, since , so far, it seems like a try on !