Ambulance crews can experience a range of issues which can affect response times, the service said.
"These can include (but are not restricted to) traffic congestion, road closures, poor weather conditions, pedestrian activity, lack of house numbers etc," it added.
Mr Donnelly said the paramedics told him streets in Turf Lodge were often blocked for all emergency services.
The family now want to raise awareness of parking issues in their area.
The couple's daughter, Aimee, said there were unanswered questions.
"My mummy was in cardiac arrest, and every second counts," she said.
"If the paramedics were able to get there even 20 seconds earlier, would the outcome have been different? It’s the same question over and over. And we’ll never get the answer to it.
"I do believe it made a difference. This isn’t about blame, this is about raising awareness of where to park."
The Social Democratic and Labour Party councillor for the area, Paul Doherty, has been trying to raise awareness of the issues.
"Residents in Turf Lodge have been plagued for decades with issues around parking and congestion. The infrastructure is outdated and the roads are not fit for purpose," he said.
"We can’t have a situation where emergency services, be it an ambulance, be it a fire service, can’t get into this area to attend to people who are at real risk."
The Donnelly family have requested meetings with the DfI, Housing Executive and Belfast City Council to discuss practical measures such as double yellow lines.
The DfI confirmed it had received the councillor's request for a site visit and also appealed for drivers to be considerate when they park.
It comes as a new pilot scheme from Belfast City Council aimed at stopping bad parking in south and east Belfast began in October.
Drivers there could face fines and possible prosecution for bad parking.
The Donnelly family said parking was also an issue when the funeral company brought Philomena home.
Mr Donnelly said the car could not get around the corner.
"Aimee had to go up the street and find who owned the car that was parked while Philomena was in the back of the funeral director's car, waiting to come home to rest," he said.
On the morning of the funeral, the family said they had to knock on doors to get cars to move, "just for that bit of dignity at the end".
The Northern Ireland Ambulance Service said: "We would like thank the public for their consideration and support when encountering ambulance crews who are responding under emergency conditions ie blue lights and sirens.
"In such circumstances, time is of the utmost importance but equally, the safety of our staff and all road users is paramount."