If she followed her brother and joined him in St Helier, he may have taken her out and about and she could have met William socially perhaps in the park when band played? on the bandstand at weekends on their days off.
Plymouth to St Helier not far on the ferries, if a little choppy! I have found in the past a lot of Devon people going over for work, or with employers?
I am still trying to work out how my great grandparents met. He was working near Honiton, and she was from Bovey Tracey. All I can think of is that he had a job where he went to France with his employers, who had connections with Dinard. He was a groom at the time. we inherited an old album, presented to him when he left his employes, inside was a mystery photo which took years to identify, of Dinard. I think she went to work for someone in Tavistock, and perhaps travelled with her employer to Dinard at the same time? Met on the boat? corresponded by letter, married in her parish which was Highweek, where her parents had moved to. Dinard was the Riviera of the north in the late 1800' apparently!!
We shall never know, but I am glad they did!! They were married for 61 years before he died.