Sylvia Lancaster campaigned tirelessly following her daughter's murder in Bacup in 2007, devoting her life to a foundation in Sophie's name.
The Sophie Lancaster Foundation campaigned to promote tolerance and stamp out prejudice, hatred and intolerance.
In a statement on the charity's website, they said: "This is the hardest statement to write. It is with great shock and disbelief that we announce that Sylvia Lancaster has passed away. She died early this morning in Blackburn hospital.
"She had suffered from ill health for the last couple of years, but her death was sudden and unexpected. Sylvia had such a powerful life force; we cannot imagine a world without her in it."
The tribute continued: "Following Sophie’s brutal murder, Sylvia put her energy into championing people from alternative subcultures and creating educational programmes to tackle prejudice and intolerance.
"She worked tirelessly to combat the inaccurate and lazy stereotyping that all too often leads to violent prejudice and promoted a culture of celebrating difference; something that leads to safer communities for us all.
"Sylvia was formidable. She challenged authority and fought for what she believed in. Her legacy is that Sophie will never be forgotten, and her daughter’s name will always represent her mission – to Stamp Out Prejudice, Hatred and Intolerance Everywhere.
"She will be sadly missed.
"There will be much to say over the course of the next few months. Initially all our thoughts are focused on supporting Adam and his family in the coming days and weeks.
"Hold those you love a little bit closer today.
"We are finishing for the last time using Sylvia’s sign off. Love and Light, The Sophie Lancaster Foundation Team."
Ryan Herbert was 16 when he was jailed for life for murdering the 20-year-old as she cradled partner Robert Maltby’s head in her lap.
They were targeted by a gang of teenagers in Stubbylee Park simply because they dressed differently.
In March 2022, the Parole Board decided Herbert could be released on licence, 15 years after he took part in the "vicious" attack.
Sylvia told the PA news agency: “The reality is obviously it’s never going to be enough.
“He had to come out some time and unfortunately it doesn’t seem long enough but that’s the reality of the situation and you’ve got to deal with it.”
Brendon Harris, Ryan Herbert and four other teenage boys “savagely and mercilessly attacked” Robert Maltby during the early hours of August 11, 2007.
Gap-year student Miss Lancaster rushed to help her boyfriend as he lay unconscious and shouted at his attackers to leave him alone.
Herbert and Harris then turned on her, subjecting her to a “sustained and vicious attack” which involved her head being kicked and stamped on until she lost consciousness.
Miss Lancaster never regained consciousness and died in hospital 14 days later.
Both men were sentenced to life in prison, with a minimum of 16 years three months for Herbert and 18 years for Harris.
However, in 2020, Herbert had his tariff cut to 14-and-a-half years when a High Court judge concluded he had made “exceptional progress” in jail.