A friend of mine who lives on the other side of the country has come to me for advice as she knows I was in the same position last year. She lives in a semi-d in a touristy part of the country and next door is now an airbnb.
The same happened to me and it was 6 months of hell, constant parties and even when they were not on, the worry and the frequent occurance that the people staying there would come home drunk at 3am and start making trouble.
When it happened to us, we contacted the landlord (who was well aware but was getting increased rent so turned a blind eye), the council (who were great but took 6 months to get it to stop) and airbnb who said they would not take down the listing despite it not having planning permission because they are "unable to take further action or mediate disputes regarding violations of local laws or 3rd party agreements".
Is there any other advice that you would give to her apart from calling the council? Its the route we took but honestly if we knew how long it would have taken we would have sought legal advice at the beginning. Is there a legal route she can take to get it shut down quicker than the council will?
I had some great revenge fantasies while it was happening like getting out my sander at 7am after their guests were up late drinking and causing a racket but just like us she has nice other neighbours so I doubt she would do that