Miriam Mason-Sesay was coming to the UK to fundraise for EducAid, a charity that supports several free schools in Sierra Leone. Her son Kofi was due to start a short-term placement at St Simon's Catholic Primary School during her stay.
Headteacher Elizabeth Inman reluctantly cancelled their visit, even though both visitors had tested negative for Ebola in a screening, and health officials in the area said there would be no risk of contamination.
In a statement, St Simon's told Premier: "It is with deep regret that the school's governing body had taken the decision to cancel the charity's visit to the school.
"It is unfortunate that some misplaced anxiety and misinformation about Ebola, amongst a small group of parents, has been circulated amongst the wider parent body.
"The school has sought, and received, assurances from the relevant health agencies that the visit would pose no risk to health. Despite these assurances, this has not alleviated the concerns of the group, leading to the cancellation.
"The school will continue to support EducAid, as it has for the last seven years, by encouraging all parents to give what they can."
There have been more than 2,000 reported cases of Ebola in Sierra Leone so far and more than 600 deaths, according to the World Health Organization (WHO).
Sierra Leone has a population of more than six million.
More than 3,000 people have died since the Ebola outbreak began in West Africa in December 2013.