Acting coincidence

My sister was married to a naval doctor and the family was posted to Mauritius. While there, my sister joined the naval base's drama society and took part in a play called "Wait until Dark". I have always been involved in amateur dramatics and many years later was doing a play with a different company from my usual one. Over a drink after rehearsal, I fell into conversation with the lady playing the lead and we talked about plays we had been in and I said that one of my favourite role had been the part of the blind girl in "Wait until Dark". My companion responded that she, too, had played that part many years ago when she and her naval husband were posted in Mauritius. It turned out to be the same production that my sister had been in.......