It was a little more than three years ago that Sophie's mum, Claire, spotted a poster in the Mailcoach appealing for players to join the Northants Centurions baseball team.
It was something that Willis Jnr was very interested in, so she went along to give baseball a try, and the rest is history.
So much so that Willis is this week playing for Team GB in the European Baseball Championships in Montpelier in the south of France, which start today.
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"My mum saw the poster and sent me the photo asking if I was interested," said Willis.
"I went to the next session on the Tuesday, and haven’t looked back.
"I’ve been training and playing with the Northants Centurions at St Crispins ever since.
"I’ve played loads of different sports throughout the years and just really enjoy baseball, with the skills coming quite naturally to me having previously played for the Northamptonshire under-17s cricket team.
"I had also been in the England Rounders team since 2018, therefore playing cricket and rounders definitely gave me great transferable skills for baseball."
Willis is a Loughborough University student where she is studying Sports Science and Physical Education, and she also plays for the university's baseball and softball teams that won the BUCS national championships in March.
So how did the GB call come about for the former Caroline Chisholm School pupil?
"Trials were announced so I thought I would go for it," said the 20-year-old. "I went along and was selected for the first training squad.
"We had indoor training sessions throughout the winter and have had further trials and selections, and after training hard to improve my skills I was selected for the final travelling roster."
Head of the PE Department at Caroline Chisolm, Joe Rich, is delighted to see his former pupil’s success – and not surprised.
“Sophie has been a phenomenal student, and she demonstrated the highest level with her attitude and perseverance,” he said.
"We had no doubt that she would go on to be successful in anything she chose to turn her hand to. We wish her all the best.”
Team GB were due to play the Czech Republic on Wednesday (Aug 3), the Netherlands on Thursday (Aug 4) and hosts France on Friday (Aug 5).
They will be hoping to finish the four-team group in the top two and reach Saturday's final at the Greg Hamilton Baseball Park.
Their progress can be followed at https://www.wbsceurope.org/en/events/2022-european-womens-baseball-championship/home
Anyone wanting to get involved in baseball at either youth level or adult level in Northampton, please check out the Northants Centurions website at https://www.northantsbaseball.co.uk/ or contact the club on at the Northants Centurions home page on Facebook.