Captain Sir Tom Moore’s daughter said his heart would have been "broken" to hear about trolling the family received.
Hannah Ingram-Moore said she could not tell her 100-year-old father "people are hating us" after his incredible fundraising efforts during the first lockdown.
The Second World War veteran died at Bedford Hospital earlier this month after testing positive for COVID-19.
Captain Sir Tom captured the hearts of the nation by walking 100 laps of his Bedfordshire garden before his 100th birthday in April last year, raising more than £32m for the NHS.
Ms Ingram-Moore told BBC Breakfast: "We really had to use our family resilience, our emotional resilience, and we never told him because I don't think he could ever have understood it.
"I think it would have broken his heart, honestly, if we'd said to him 'people are hating us'.
"I couldn’t tell him, because how do you rationalise to a 100-year-old man that something so incredibly good can attract such horror?"
She said the trolling became "pretty horrific" and "really did hurt" but made sure "it didn’t come close to him".
"We contained it within the four of us and we said that we won't play to them," she added.
"They will never make this amazing thing negative, not ever. We won't let them."
Cover image: Captain Sir Tom Moore at AFC Harrogate with his daughter Hannah (Picture: MOD).