Friends of Ms Folwell said she had continued working in her role as chairman of Conservative Thirsk and Malton Constituency Association up until a few weeks ago, having been diagnosed with cancer earlier this year.
Among those taken aback by her death has been classic-winning trainer Mick Easterby, who had Ms Folwell's horses at his Sheriff Hutton yard. Mr Easterby said would remember his friend as someone who took delight in treating her horses.
He said: "I was very close to her, she used to come and see me every week for a ride out. I used to take her to Ayr races and she really enjoyed it, she was a marvellous and very knowledgeable person with a lot of wit. "
North Yorkshire County Council deputy leader Councillor Gareth Dadd described Ms Folwell as "a true friend" to both himself and his partner, Darlington MP Peter Gibson.
Cllr Dadd said: "She provided civility and decency in times of turmoil and trouble. Passionate about horse racing, her tips in that field were as good as her political tips to ambitious politicians. For her counsel, friendship and integrity we shall be forever grateful and we shall miss her terribly."
Thirsk and Malton MP Kevin Hollinrake said he had been devastated to learn of her death as she had been "a constant source of support and sage advice" and made herself available to anyone in need.
He said: "In every capacity, in every role she played - friend, fellow member and colleague - she was a truly wonderful person. She combined boundless energy, a sunny disposition, selflessness, wisdom, compassion and humour. "
A spokesman for Thirsk and Malton Conservatives said while Ms Folwell had held the position of chairman for two years, she had been deputy chairman before that and her involvement with local branches dated back more than 25 years.
Association president Kenelm Storey said he, his fellow officers and all the association members were deeply saddened by Ms Folwell’s "untimely death".
“Linda has been a stalwart of this association over very many years and we are immensely grateful to her for everything she has done for the Conservative Party in this constituency, and also more widely across the North Yorkshire region.
"Our thoughts and prayers of course are with her family and all her many friends – among whom we feel fortunate to count ourselves. She will be very sadly missed. Hers will be difficult shoes to fill.”