"I was determined that if no-one was going to do it for us, we'd do it ourselves," says the 79-year-old grandmother, firmly. "Stephen was my child - I wasn't just going to abandon him."
Stephen took his first seizure at the age of nine months and after extensive tests, doctors told Madalena and her husband Archie, who also had a daughter, Alyson, that their baby boy had brain damage. When he was nine, Stephen developed scoliosis, or curvature of the spine, which would eventually mean the use of a wheelchair.
"When he turned 16, there was nothing available to help him and that just wasn't right," says Madalena. "A group of parents got together and decided to build our own centre, which could help families with severely disabled children get the education and physiotherapy and life chances they needed."
Despite being turned down twice by the then Scottish Office and Strathclyde Regional Council, Madalena refused to give up, rallying support, gathering petition signatures and lobbying councillors. After six years, she was successful and the £1 million Aveyron Centre in Hamilton was given the go-ahead. Madalena and a group of dedicated parents hired staff and overcame negative attitudes to make the centre a success.
"There was a real sense of - well, what can you lot do? You're only parents," recalls Madalena. "But we knew our children and how they felt and what they needed. We gave parents a voice."
Sadly, Stephen died, aged 28, in 1999, and Madalena retired from the centre shortly afterwards, handing over the reins to the national charity Sense Scotland.
"I was proud of what we achieved," she says, with a smile. "I firmly believe Stephen's purpose in life, his reason for being here, was to make a difference and he did. Others now benefit because of him."
Maureen Hill, who helped Madalena to set up the Aveyron Centre with the support of fellow parents Margaret Stirling, Moira Tait, Helen Barrie and Norrie Flannagan, says: "Without Madalena, the Aveyron Centre would never have got off the ground. It was her drive and enthusiasm which made it all happen. She is a very strong, determined lady. She is one in a million."