“People think I’m a bit odd,” Sr Cora Richardson announces cheerfully. She takes her feet out from under the table to show me her shoes. “My shoes belong to a sister who died,” she explains. “They’re a little big, but I wear thick stockings. I think you have to be odd and stick your neck out a bit in life.”

Last year, Sr Cora (78) returned to Ireland after spending close on half a century in South Africa as a missionary Sister of the Holy Rosary. Earlier this week, at a ceremony in City Hall presided over by Sabina Coyne, wife of President Michael D Higgins, she was one of some 70 former Irish missionary brothers and sisters acknowledged for their services overseas.

Sr Cora grew up in Rossduff, Co Waterford, not far from Dunmore East. Their household took missionary magazines, such as the Far East and the African Rosary, which she credits with making her aware of a wider world.

“The main thing in my head is that even as a child, I felt very blessed, and I wanted other people to have the same chances as me,” she says.

We’re talking in the house in Artane that is acting as a temporary home for four Sisters of the Holy Rosary, while their bigger residence is being extended. Worldwide, there are less than 400 sisters in the community; half of whom are African. The house being extended will, over time, accommodate some 50 retired sisters.

Sr Cora finished school at 16, and went to Belgium for a year to learn French. She had already informed her parents she wished to enter as a missionary sister. “We’re not nuns, we’re sisters,” she says briskly. “Nuns are another breed.” Her parents insisted she first receive an education before they would consider her desire to enter religious life.

“So I did law and history at UCD, and I lived in a flat in Merrion Square. In those days, the park was locked, but we had keys. It was a wonderful life. And meantime, I fell in love with someone and when I finished college, he asked me to marry him.”

Despite all this, she couldn’t ignore the pull of religious life. “God had put his hand on me in some way. I can’t explain it,” she says now. And so, not really expecting to stay, she entered the missionary order of the Holy Rosary in Killeshandra, Co Cavan.

“The hardest thing I ever had to do in my life was say goodbye to that young man,” she says. Her father stopped the car so she could call him from a public phonebox en route to Cavan from Waterford. “He had come over to the house the night before to say goodbye, but this was the real goodbye.” She cried in the phonebox while her father waited outside in the car.

That was the beginning of what turned out to be the rest of her life. She did become a nun, and as the order trained its sisters for overseas work, shortly after being professed, she was sent to South Africa.

“I was the first sister from our order to go out by plane. Everyone else had gone on the ship. It took three weeks. I would have loved to have gone on the ship,” she says wistfully, more than once.

She worked as a teacher in various communities near to Johannesburg for many years. Apartheid was still in place, so the schools were not mixed at that time.

“I never agreed with it, naturally, and I was shocked to discover that some sisters wouldn’t even know the people in the kitchen – the African people who did the cooking.”

By her own admission, she says she was “always in trouble. My phones were tapped and my letters were opened”. This was because she tried to be inclusive. One of the things she did was start adult education classes for members of the black community in Sharpeville.

“Straight away I met opposition from people, including the local parish priest. I wonder should you put that in? I suppose it’s a long time ago now. The whites thought apartheid would last forever.”

It was seven years before she came home for the first time. “I was so struck by the waste – the waste of water and electricity. I still am.”

Sr Cora returned to Ireland for good less than a year ago, bringing with her only one suitcase and a handbag. “I gave away almost everything I had before I came back.”

Has she got anything she’s kept over time? She thinks. “I have a little penknife that I had from before I entered,” she volunteers. “I use it to peel apples.”

She is still in a kind of reverse culture shock. “I’m very ignorant about Ireland. People talk about things and I don’t know what they’re talking about – the Tiger, things like that. I didn’t really keep up with news from Ireland when I was away. There wasn’t the time. It’s a bit of a mystery to me how the country is functioning.”