Long-lost aunt found after 40years on an antipodean boat

When I was about 4 (living in North London) my Geordie aunt (Elizabeth Bowman) was a '£10 pom' and emigrated to Australia (1958) sleeping on the deck. Never saw her again, nor post, nor photos... When I was 14, a woman sat opposite me on a bus in Watford (where I grew up) - her face looked familiar and she seemed to think from her expression I was familiar - we did not speak. When 24 (now living in Liverpool) I married a girl from Chester. Her elder sister married 2 years early and emigrated to New Zealand. When 44 and living in Berkshire, my wife and I went to NZ to see her sister. After about a week in Christchurch with them, we hired a car and drove off exploring. After several days wandering (driving aimlessly and booking motels) we ended up in Queenstown one afternoon. We just missed the last steam ferry on the lake (it was pulling away as we got to the port gate). After much umming and ahrring we decided to stay overnight. After a leisurley lie-in, we wandered down to the port and got the next steamer sailing there was (of several during the day). It was hot and we sat on the deck. In mid-lake, an elderley lady came up from below and sat on the seat directly behind me (many others to choose from!). I turned round tapped her on the shoulder and for some reason said 'Hello Aunty Betty'! It WAS my long lost Aunt on an australian coach tour of New Zealand with her 3rd husband. She had lived in many parts of Australia and just happened to be on that particular steamer with a coach trip on that mid-week day in that NZ town on a holiday at that time. She also confirmed the 'meeting' on the bus in Watford which she remembered vividly too. I am a professional statistician - this series of events has ma ind-bogglingly low probability of happening (under any random assumption)...