What she aught to do is rent another place, with NO NEAR HOUSES - for 5 months...
a fence isn't going to do it - I'm sure he has listening devices that will enable him to hear conversations in the house.
Just rent another place, bake him a cake, take it over and say “Golly, sorry we're going to miss your stay. But do have a great vacation.”
THEN, if he follows and rents another place close by - I would think that could be legally called ‘stalking” - altho’ I don't understand why this isn't. He rented the place for one reason, to spy on her.
But she should think about moving altogether. Some one who has become as famous as she has, especially when considered a threat and a target of some very evil people, she should not be living where there is a house just 15 feet away. There would never be safety for her and family.
Heck, I'm far from famous, but I couldn't stand having someone living that close to me. I love my privacy. I look out and all I see is sky and forest and sun...and the furred and feathered folk. Best neighbors that can be had.
LOL -- this is just some wannabee author, not James Bond.