Consequently, that day Wilson the teenager simply smiled with a sense of contentment that she was at liberty to do as she pleased, regardless of her coach's verdict.
"I didn't want to get to the moon with my game. I just wanted to have some fun with it."
She certainly did, for at least 50 years, and still tries to serve and volley once a week at the revamped Westend Community Tennis Inc courts at Ebbett Park, Raureka, Hastings.
"I played squash [at Havelock North club] when I was in my 20s but I switched to tennis because I wanted to get out in the fresh air," says the 78-year-old grandmother of Hastings whose husband, the late Rex Wilson, didn't play tennis but enjoyed recreational sailing on weekends.
Shirley Wilson joined the now defunct Parkvale Tennis Club in Hastings but when it ran out of members more than two decades ago she became a member of Westend.
A cousin, who played squash, gave her some timely reinforcement that getting married and having children didn't have to sound the death knell for her chosen sport.
In fact, the family business, EW Wilson Construction, built two additional squash courts at the Havelock North club as well as those at the Karamu High School.
She fondly recalls beating successive generations of schoolboys when Wayne Wooster was the teacher in charge of squash at Karamu High.
For someone who enjoyed C grade tennis, Wilson went on to join tour groups from Christchurch to play in Australia.
"Dorothy Lumsden asked me to go and we played in Outback Australia on some massive courts," she says of Lumsden who is the secretary of the Bay veterans' association.
Wilson's eyes are not as sharp these days and she doesn't get out on to the courts as often as she would like.
"I've still got energy to play but I'm losing sight of the ball coming over the nets so it just disappears," she says with a wry smile.
Consequently, it thrills her to hear the Westend courts will be accessible for all at a minimal cost.
"I would like to see the courts used to boost old members," she says of the Westend that has three courts, down from about 10 in the halcyon days.
"Westend used to be one of the first in Hastings and it joined up with netball who had their big anniversary not long ago."
Wilson, "a volunteer all my life", played tennis socially while raising two rugby-playing boys - Allan, 53, of Sydney, and David, 51, of Tauranga - and a hockey-playing daughter, Claire, 46, who lives next door to where the family's business property was based in Hastings.
Wilson is all for people possessing a "killer instinct" in sport to win, however, "someone always has to lose but you lose with a smile," she says, looking forward to a flurry of activity at the Westend courts from this weekend despite the inclement weather.
