Fiona became emotional when she spoke to Holly Willoughby and Phillip Schofield about the pain of losing both her parents to the disease, and revealed her fear of inheriting Alzheimer's herself.
Fiona's mother Amy began developing early onset Alzheimer's at 53, two years younger than Fiona is now, before she died tragically in 2006, aged 74.
The 55 year old revealed the moment she realised something was happening to her mum, 'I noticed mum's Alzheimer's at Christmas. She was really cold, there was no food in the house, she'd have the Christmas tree up in November so it was very unusual.'
'Dad was beside himself and little did we know he had it too. Bizarre presents, my brother had an orange ladies jumper.'
Heartbreakingly, her father, Phil, was also affected by the condition from his early 60s and spent the end of his life in a warden-assisted flat, before moving to a psychiatric hospital where he died in 2012, aged 76.
Phil didn't know he was suffering from the disease, and the family found out after an incident that could have so easily turned into a terrible accident.
Fiona recalled, 'Dad was found by the police because he was driving, even up to the end he was asking where his car was because he loved driving. He was driving erratically up the street, they breathalised him, he hadn't been drinking alcohol then they bunged him in a cell and told no one.
'The next moment we saw him we came to visit mum and he came blundering in and we asked him where he had been and he said: "I've been in a police cell."
'We didn't know why - he had Alzheimer's at that point. He didn't know why, we didn't know why. I still have nightmares about it.'
Fiona now fears for herself and becoming a burden to her husband and two sons, 'I need to sort out an action plan that can be used if I "disappear"... Of course I fear inheriting the disease with my family history, and I sometimes wake up in the night feeling anxious and worried about it.'
For the moment she is concentrating on lending her support to the charity Alzheimer's UK, who have just released their touching new advert for Christmas called Santa Forgot, which depicts Santa with Alzheimer's.