A 19-year-old died from cervical cancer after she was refused a smear test because doctors said she was too young to get the disease.
Aspiring model Sophie Jones died on Saturday morning after she was diagnosed in November.
She had suffered for months with severe stomach pains and repeatedly asked for a smear test, but doctors said her symptoms were caused by the intestinal inflammatory condition, Crohn's disease.
Sophie, from Eastham, Wirral, was admitted to hospital when her condition worsened. When doctors found the cancer it had already spread to other parts of her body.
Now Sophie's family and friends have started a petition to lower the age of cervical screening from 25 to 16.
Sophie's sister Steph said the family wanted to give girls the option to be tested when they knew something was wrong.
She said: "It's totally wrong that people are getting refused even when they know something isn't right. Everybody knows their own body, and Sophie knew she wasn't well."
The lower age limit for routine testing in England is 25 because the condition is so rare.
According to Cancer Research UK's most recent statistics, no girls under the age of 20 died from the disease between 2009 and 2011, meaning Sophie was one of the youngest ever victims of the disease.
The Sophie's Choice online petition has already collected more than 18,000 signatures since it started on Saturday, and if more than 100,000 people sign it a debate will be started in Parliament on the subject of cervical screening.
Steph said: "Sophie was just the life and soul of everything, and just lit the place up. She was always a very calming influence on everyone around her, and she loved being with her friends.
"This should never, ever have happened to her."
She added: "Sophie said she would fight it all the way to the end. She was still in high spirits even on the morning she died."
Several fundraisers had been held to help her family during her illness, and Steph said plans were in place to use some of the money to take Sophie on holiday as a final farewell, but sadly she died before she had the chance.
Family friend Pamela Keelan, who started the petition on the day Sophie died, said she hoped they could make sure other girls did not suffer the same fate.
She said: "Sophie was told she was too young to possibly have the disease, but by the time they diagnosed her it was too late."
She added: "I've got a mind to take it to Downing Street, to David Cameron, and hopefully it will make a difference."