As far as I know Laura's second name was Anna, not Hannah, at least according to the BMD, but of course it's possible this became distorted over time because it sounds so similar. Her birth was certainly registered in 1878 at Abingdon, Oxford.
Sorry if I'm being slow... do you mean that Bertha Clinkard sailed to England in 1938 and Laura sailed to the US in 1950?
If you can make out the name of Laura's nephew that would be brilliant, but please don't worry if you're too busy. I am based in England too.
Many thanks for all your help.