A 13-year-old girl will be cycling 464 miles over six weeks - the same distance from her home in Jersey to the hospital where her sister is receiving care.
Rosie Hargreaves is raising money for Family First Jersey, the charity that has helped support her family as her sister receives specialist treatment off-island.
On Rosie's bike throughout the challenge will be Brave Bear. Her sister has an identical one with her in hospital.
It's to remind them that even though hundreds of miles separate them, they are never truly apart.
A target of £500 was set, but that has already been smashed!
Rosie said:
"I'm doing this to raise money for Family First, to help other families be supported financially when their child has to go away from Jersey.
"I wanted to do something to support Family First as they supported my family so much.
"I can't believe how much money we have raised. I doubled my target in just 48 hours, I'm beyond grateful, as I know how much this money will really help.
"Even £15 would be the train ticket from Gatwick to the hospital in England."
Rosie is due to begin her challenge in mid-August.
Channel Islander abandons Bordeaux as the flames 'arrive at the city's gates'
Man in hospital after serious assault at Havre Des Pas festival
No increase in domestic abuse reports in Jersey during World Cup
Nowacki wins Jersey’s first Commonwealth Games medal in 36 years
Commonwealth Games: Nowacki into 100m breaststroke final
Thousands expected at Havre Des Pas Festival this weekend
Channel Islands face 'physical' Poland test
Price of heating oil and other fuel increase by more than half in a year
