In 1974, she co-founded the World Team Tennis (WTT) Pro League where men and women play professional tennis on the same team and contribute equally to the outcome.
Boltersdorf's clients include several clubs in Germany's elite Bundesliga soccer league and the national men's handball team, which won the world championship in 2007.
With more than 18, 000 miles on the clock, Roy Hodgson's men have effectively travelled three-quarters of the way round the world to reach the Europa League semi-finals and the journey has not been without its pitfalls.