Claire Squires, who has raised more than £400,000 through her Just Giving web page since her death during the London Marathon, was running in tribute to her dead brother.
The 30-year-old from North Kilworth, Leicestershire, collapsed less than a mile from the finishing line during this year's race.
Since then, tributes and donations have been pouring into Squire's charity fundraising page, bringing her total for the Samaritans to more than £400,000.
Friends of the tragic runner believe she participated in the marathon in tribute to her brother, Grant Squires, who died in 2001 from an overdose at the age of 25 after becoming depressed following the death of his girlfriend, Heidi Richardson, in a car accident which he survived.
The family of Squires said in a statement: "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."
Squires had originally raised £650 for the charity before the race, but since her death thousands of people have made donations, taking the total to almost half a million pounds.
Squires, who worked at Moko hair salon in Church Street. Market Harborough, Leicestershire, had also climbed Mount Kilimanjaro in 2010 to raise funds for the RAF Association.
On her behalf. the RAF Association said in a statement: "Claire was a wonderfully vibrant and energetic person, who was a keen charity supporter and loved by all who knew her.
"In 2010 she climbed Mount Kilimanjaro and also took part in other fundraising events in support of the RAF family in recent years."
Samaritan chief executive Catherine Johnstone said: "We desperately wish that it was not under these circumstances, but we have been overwhelmed by the response from people donating in Claire's memory.
"These donations will be put into a tribute fund and, following discussions with the family, will go towards projects they feel would have been important to Claire."
Along with donations, tributes have continued to be posted on Claire's JustGiving page. Kathryn John wrote: "RIP you very brave lady. I used to work for the Samaritans - wonderful charity. You have done more than you know for them x."