Mrs Waterman was well-known as a fitness trainer to celebrities. Her clients included Kelly Brook, Denise Van Outen and Rachel Hunter.
Natalie Appleton, who was previously part of the pop group All Saints, wrote in tribute to her close friend: “There aren’t enough words to express how much we will miss you.
“You were my rock, my inspiration, shoulder to cry on and always there when I needed you, you never failed to make us laugh.”
In March this year Mrs Waterman spoke at an event in Parliament as part of Brain Tumour Awareness Month, where she lobbied for more trials and funding “so that people can have the same opportunity for treatment that I did".
She had promised her husband she would fight to find a cure, she told the JC.
