But her true dream came true when she qualified for the 2012 Olympic Trials.
"She made the cuts way in advance," said Nick. "I spent years trying to make the cuts months before the deadlines, and she did it like two years in advance. You could just see the same giddy feeling I had four years ago, but she was just a little better. It was really cool to be going again and have her with me.
"We had the whole family down there. My mother and father, my grandmother and even my aunt who had never been to a swim meet in her life was loving it."
It didn't take long for Maggie D'Innocenzo to be wowed by the experience of the Trials.
"The minute we walked in I looked around the pool and said, 'Oh my God, this pool is so big!'" she remembered. "Then someone said, 'That's just the warmup pool.' When I walked into the real pool I couldn't believe it. It was like being at the (Boston) Garden. I felt like a superstar."
While the biggest names in Olympic swimming were walking past her, Maggie was calmed by the sight of a familiar face.
"I walk in and I'm just start struck by Michael Phelps and Ryan Lochte walking past me," said Maggie. "And then I just see Nick walk by. It made things a little less scary to have him there with me, cheering me on."
What dazzled the younger D'Innocenzo the most was the scale of the event.
"I have never seen anything like it," said Maggie. "To be in the atmosphere of Olympians was something special.
"I got to my parents' seats and you hear this cheering. They had spotlights and music, then all of a sudden flames started shooting out of the sides of the pool. There were pyrotechnics. I was thinking, 'This is a swim meet? This is what happens at Red Sox games.' They just don't have this at swim meets."