She has registered for three events in the State New Zealand Ocean Swim Series over the summer.
She explained her road to recovery: "After several visits [to the chiropractor] and my back continuously going out, I figured it was not going to work without something else to complement it."
Accompanying her children to swim training at Silverdale's Northern Arena was the inspiration Finnegan needed. "I had a chat to them about swimming and whether they felt it would be okay for me to do. That was January 31, and I haven't stopped since." Swimming proved to be a relief and the results came quickly.
"It didn't take long before the muscles were less stressed but mainly that my shoulder stopped dislocating. It was lovely ... It almost made me feel weightless, which was wonderful when I was normally in continuous pain," she said.
Finnegan's coaches at the Northern Arena encouraged her to enter the NZ Ocean Swim Series as a goal to train for. She said being committed to the competition really helped with her motivation.
"I swim five times a week for over an hour each session ... I have now become a swimming junkie. I actually miss it when I don't get to swim at least a couple of times a week."
Finnegan was one of 1600 swimmers who took part in the recent State Harbour Crossing, which was a "surreal" experience.
"I was absolutely elated when I came out of the water after crossing Auckland harbour. It was such a huge buzz. I can't wait to take part again."
Scott Rice, the State NZ Ocean Swim Series event director, said comeback stories like Finnegan's were awesome to experience.
"The look on Ali's face at the Harbour Crossing finish line said it all," he said. "She represents everything our series is about - exercising to achieve positive, health-focused goals while having fun."
The second event in the series is the Bay of Islands Classic on December 7, which is expected to attract more than 800 entries.
In the swim
What: State Bay of Islands Classic
When: Saturday, December 7
Where: Paihia, Bay of Islands
Event options: I'm Going Long, 3.3km; Give It A Go, 300m; Step It Up, 1000m; State OceanKids, 200m.
Online: www.oceanswim.co.nz