The terrifying incident brought home just how much "I need to be around for my son, because I had watched him nearly die and I didn't want him to go through what I had just gone through."
At her heaviest, "I would go to bed every night thinking that I was going to have a heart attack and die."
Bowden said she struggled with a food addiction from as young as she can remember. She suffered cruel taunts from some other children, she said, which stung even more as she entered her teens and became more self-conscious.
She said she increasingly turned to comfort eating after Ashar, who has nonverbal autism and does not speak, was hospitalised at 15 months with a serious illness in which blood vessels become inflamed.
"I started eating and eating... that was just how I dealt with being a single mum... [having] a child who wasn't well."
Bowden said she put on at least 20kg a year and feared "I would have been dead by the time he was 10".
Her typical diet, she said, was six pieces of peanut butter toast for breakfast followed by a pie, a tub of ice cream and a block of chocolate for lunch, meat and potatoes but no vegetables for dinner, plus snacks of chips and biscuits throughout the day.
The physical toll was huge.
"I couldn't walk to the car comfortably... rolling over in my bed was a struggle... I was always tired. I couldn't catch my son if he ran away from me, I had to get strangers to catch him one day."
Her self-esteem hit rock bottom and she became even more self-conscious.
"When you're that overweight... getting out of the car... walking to the (supermarket), standing in line, you're conscious people are looking at you because you are so different to the norm."
Bowden reached 174.3kg by March last year, before dramatically turning her life around.
She started on a diet plan, including protein bars, meal replacement shakes and steamed vegetables, and lost 36kg in 12 weeks.
She also started exercising, walking a 120-step climb near her home at Mangawhai, north of Auckland. Starting out with the aim of making it up the stairway without stopping, she graduated to running up it. Joining a gym, she began boxing fitness training and powerlifting.
Through diet and determination - plus "looking at my son and knowing that he deserves better" - she dropped to 87kg within 12 months.
Bowden has kept the kilos off, weighing in now at 89kg after packing on some muscle but is about to lose around another 4kg on Monday in an operation to remove excess skin from her stomach.
Working out a minimum 12 times a week, she has a treadmill and boxing bag at home, and the gym is "my happy place". Her powerlifting is progressing and she has managed a 120kg deadlift. And she is working towards an amateur boxing bout.
Her diet is now clean, with plenty of fruit and vegetables, and nuts for snacks. "I still treat myself... I [have] finally found the balance between too much and starving yourself of living."
She plans to do nutrition and personal training courses, and help others transform their lives. "I want to be a PT to the people who are really struggling."
Bowden is determined not to return to her old lifestyle. "There's no point in going back to a miserable life".
"I'm healthy and it's made my son more healthy because I take him for walks every weekend now and we're always doing something and happy."
A consequence of her dramatic weight loss has been excess skin on her stomach and limbs.
The "4kg weight hanging off my stomach" restricts her ability to exercise and clothes she is able to wear, she said.
Unable to afford the excess skin removal surgery, she applied for public health funding but was unsuccessful, she said.
She fundraised through Givealittle, which raised over $2000. Then, she said, out of the blue she received a private message on her Facebook page from a Samaritan offering to give her $40,000 for her surgery.
"I didn't think it was real... But then the money went through - I was like, oh my God... I'm really, really grateful."
The donor, from her Mangawhai community, had "followed my journey".
"She knows about my son. She's always seen me struggle with weight. And she saw me lose it. And she just went, that she has this money, but she wants to remain anonymous and that's her only ask."
Bowden said the operation on Monday will be for several hours and involve two surgeons. "They will cut out my middle piece of skin and stitch me back together." She expects to be in hospital for two nights.
She plans to have excess skin removed from her arms and legs some time in the future.
Bowden said she is trying to figure out how to repay her Samaritan.
"I want to do something special for her but I know it won't ever be...equal to what she's done for me because she's changed my everyday life... every day for the rest of [my] life."