Doing what you love is normally a solid foundation for excelling in what you do. For siblings James Boulter, a talent agent at United Talent Agency (UTA), and Katie Boulter, Britain’s No 1 female tennis player, passion and perseverance are essential. “It’s important that I love what I do as I know I’m going to put so much more energy into my everyday life,” says Katie, 28, who at time of writing is ranked 23 in the world (a career high) and has three career titles; she first…

