Since setting off from her home in South Wales in January, the 54-year-old has already walked the entire coast of the island of Ireland, the whole of the Welsh coastal path, isles of Anglesey, Isle of Man and around 20 of the Scottish islands.
Karen, whose life is packed into a rucksack with the minimum essentials, including a tent and a clothes bag the size of a washbag, was inspired to take on the challenge following the loss of both her parents-in-law to Alzheimer's.
'Alzheimer's is a disease of the brain that can affect anyone at any age at any time. It can be cured, we just need to fund the research to find it,' she said.
'My mother-in-law Alma had vascular dementia and died within six months. Within one week of her funeral, my father-in-law, Kingsley, was ringing us asking where we were and what was for tea - repeatedly. He deteriorated to such an extent, mentally and physically, that ultimately he couldn't even recognise family members.
'There is very little government funding for Alzheimer's and that has to change. In the meantime, my mission is to keep funding coming in. Let's get Alzheimer's back on top of the research list.'
On Wednesday November 13, in her fifth pair of boots, reaching around the 5,000 mile mark, Karen set off from Lochgilphead on day 300 of her mammoth mission that could take up to four years to complete.
From Lochgilphead Karen was headed first for Crinan, before looping back and heading to Kilmartin along Moine Mhòr, to spend the night. The plan was to then set out for Kilmelford on Thursday and Oban on Friday (today) where she will enjoy her first day off in five months and join the Parkrun on Saturday.
Karen commented on the generosity and kindness she has experienced since she began the challenge: 'Everyone has been so kind. It's incredibly uplifting. People just let you into their homes and their lives. It's the amazing support I have which keeps me going.'
Lindsay Caulfield, of Lochgilphead, generously gave up her bed on Tuesday night, giving Karen the opportunity for some well deserved relaxation and a night out of the cold before the next stint of her adventure and Ali and Calvin Elliott offered moral support as they joined Karen as she set out on Wednesday morning.
Karen will be the first woman to complete the challenge and commented on how she is coping: 'I take every day as it comes. If I let the enormity of it all come into my mind, if I think about how long I really am going to be away from home and my family, I know I will struggle.
'You have to look at it daily and be flexible. I try not to worry about where I'll be staying the next night or how far I still have to go. I've slept in bird hides to deserted castles. I'm eating 11-day-old bread and green cheese one night, then the next I'm staying with Lord and Lady Vesty on Jura. It's that extreme and you just have to take it in your stride,' she added.
Karen has already raised more than £46,000 of her £100,000 target and has since been made a Champion of Alzheimer's Research UK in recognition of her incredible fundraising and tireless dedication raising awareness of dementia.
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