Why would that be so far fetched? In fact, it is entirely possible the son, who "released" the diaries could have made it all up. The point being, it could be that some of the neighbours are a bunch of bullies and are jealous of the attention she has been getting. The very fact that it is in the Daily Heil is enough to lay that level of suspicion.
So you think a grieving son who recently lost his elderly mother has nothing would just make all this up and invent her diary entries about how she was terrorised by this family (including pictures of her trashed shed) just to get a spread in the Daily Mail. And that all these other ex neighbours are just making it up cos they are jealous of her?
Get over yourself – how ridiculous!
Presumably you believe Anne Frank’s diaries were fake too?!