http://www.whychristmas.com/customs/pudding.shtml
This link will give an explanation to the origins of the Christmas Pudding. I almost forgot that when we were young and before decimal currency in Australia our small coins i.e. threepences and sixpences were silver coins and were always put in the pudding when it was being mixed. Great delight when we got a coin in our piece of pudding. I was married in 1966 (the year decimal currency arrived) so I have never put coins in the pudding as our 5 cent coins are not silver.
My husband tells the story of his sister swallowing her coin and he gave her his to stop her crying. Still generous to a T.