Emily Watts' parents, Nicky and Dominic, along with her 27-year-old brother Rory, have all travelled to the hospital in Annecy where she is being treated.
It took several days for French authorities to notify her parents because she was not wearing any form of identification.
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After the heatwave come the storms, with lightning flashes illuminating the night sky across much of the country last night.
An Independence Day event at a UK base has been cancelled by the US Air Force over security fears.
British firms predict the economy should sustain a "solid" pace of growth for the rest of the year thanks to lower oil prices and inflation.