One morning, Emma Millar will be coaching Commonwealth Games gold medallist Joelle King. In the afternoon, she’ll run Racket Rascals, a programme for two to four-year olds. When the evening hits, she might be teaching an adult how to hold a squash racket for the very first time, or a teenager who’s aiming to represent New Zealand. It’s the love of the sport, and the love of coaching that keeps Millar, a former top player herself, so active in al…