But Tudor Morgan, the heir to the dynasty, is back behind a counter once again - 10, 000 miles away in one of the world's most southerly shop at Port Lockroy on Antarctica.
On a fine summer day she drives to Nihonmatsu, 56km (35 miles) from the ruined nuclear plant at Fukushima, and notes her Geiger counter ticking higher: another step in the DIY defence against radioactivity.