It is a story that has often been told, and always gets a laugh. When Joan decided to create a hospice on the Costa del Sol, her first staunch ally was Dr Marisa Martín, who had cared for Joan's husband Fred in his last days.
Marisa loved the idea but just didn't think it was possible.
"How will you raise the money?" was the obvious question.
"People will help me, there will be volunteers," said Joan.
And when Joan decided that a charity shop would be one way of raising funds, again Marisa demurred.
"Spanish people just don't buy second hand things," she said.
Marisa ends the story: "Cudeca now has 25 shops, several of them in Malaga city" (cue laughter, not least from Marisa).
That is just one of Joan's legacies. A string of charity shops, manned by volunteers of all nationalities, and contributing a large proportion of Cudeca's funds.
Cudeca itself, of course, is Joan's greatest legacy: to date the only hospice in Spain, though Joan herself knew that palliative care, what she referred to as Cudeca's "special kind of caring", should be available to everyone, and a training programme and soon-to-open research centre are also a part of her legacy.
We now know that she also left something else.
The house she paid for and lived in, adjoining the hospice, was adapted not only to her own needs but with a view to forming part of the hospice after her death.
She left it to Cudeca, and it will become Room 10, earmarked for children and people with special needs, just as Joan intended.
Thousands of people inspired by Joan helped build her legacies, and thousands of us will now ensure that they go on.