The family of Claire Squires, who died while competing in the London Marathon, today paid tribute to an "an incredible, inspirational, beautiful and driven person" as donations to her charity rose towards £500,000.
The huge surge in giving to her fundraising page came after the 30-year-old collapsed in Birdcage Walk, near St James's Park, on the final stretch of the 26.2-mile course on Sunday.
Yesterday saw the largest number of donations ever received in a single day on the JustGiving website, with more than 10,000 people donating together at any given time, the group said.
Miss Squires's family have thanked the tens of thousands of people who have donated and urged people to keep on giving.
She was running the marathon in aid of the Samaritans because her mother Cilla has volunteered with the organisation for more than 20 years.
The death comes after Miss Squires' brother Grant died in 2001. A coroner recorded an open verdict into the death of the 25-year-old, who was reportedly a drug user and had become depressed after being involved in a car crash in which his girlfriend was killed.
In a statement Miss Squires's family said: "On behalf of Claire's family and all those who knew and loved her - we would like to say thank you so much for everyone's support.
"Claire would be so happy and overwhelmed with the incredible support that has been offered by thousands of people from all over the world.
"Her family appreciate the kind messages posted online very much.
"Words cannot explain what an incredible, inspirational, beautiful and driven person she was. She was loved by so many and is dearly missed by all of us.
"For Claire and the Samaritans, please keep the donations coming.
"Don't stop giving, just like her. It's what she would have wanted."
Anne-Marie Huby, managing director of JustGiving said: "The response to Claire Squires' tragic death on Sunday has been extraordinary. Out of respect for Claire's memory, we will be donating our fees back to the Samaritans.
"We are honoured to have played our part in enabling people from all over the world to pay their respects and donate in their thousands over the last couple of days.
"Yesterday the JustGiving site saw a record number of visits, with over 10,000 people donating together at any given time. This huge wave of sympathy continues today."
Catherine Johnstone, chief executive of Samaritans, said: "This is an incredibly difficult time for Claire Squires' family and friends, and for Samaritans and all our volunteers.
"We are truly humbled by the reaction from the public following Claire's tragic death, and are overwhelmed by the support they have shown. At an appropriate time we will be speaking to Claire's family about what they feel she would have liked these donations to fund.
"We appreciate JustGiving's kind gesture to donate their fees to the tribute fund that has been set up in Claire's memory.
"Thank you for respecting the family's right to grieve during this traumatic time."
The charity's annual turnover from individual donations typically totals around £3.8 million a year, a spokesman said. Overall, with donations from companies and trust funds, its turnover is some £10m each year.
Friends paying tribute to Miss Squires, a hairdresser from North Kilworth, Leicestershire, have described her as an "inspiration" and "the most amazing person in the world".
Victoria Hauser said: "Claire was larger than life, fun-loving, bubbly, happy, cheerful, kind, giving, thoughtful. She was just the most amazing person in the world - the best friend I have ever had.
"She could never be replaced and dozens of people would feel like that - it's not just me. Once Claire was a friend, she was a friend for life and a very, very good friend."
She added: "It wasn't about a personal best or anything like that for Claire, she'd do her best - it was about what she could do for other people.
"Claire wouldn't have a clue how she is remembered. She was the most beautiful person inside and out but she had no idea about it."
Tests to establish why Miss Squires collapsed are expected to take place in the coming days.
She died with the finishing line only one bend away, after 25 miles of the marathon.
Miss Squires is the 11th participant to die since the event began in 1981.