When Cowan was 15 months old she contracted meningitis. To save her life, doctors had to amputate all four of her limbs just below the joint. At the age of 2, she was fitted with prosthetic limbs. Although Cowan has always loved to swim, she started her athletic career as a figure skater. After winning a number of medals she decided to try something new.
- On 8 September 2001, she swam 19.2 km across Lake Erie at the age of 15 as a 10th grade student at Birchmount Park Collegiate in Toronto, coached by Vicki Keith. On 7 September 2001 at 8:53 am, she walked into the 21°C waters of Lake Erie from the boat ramp at Sturgeon Point Marina, New York, seeking to accomplish one of her dreams. 14 hours 20 minutes later she climbed out of the lake, at Crystal Beach boat ramp, Ontario, having become the youngest person and first athlete with a disability to complete the swim. All of Canada embraced "this little girl with a huge heart." People from around the world contacted and congratulated her. Her response was "Anything is possible if you believe in yourself. Able bodied or disabled, there are no limitations if you are willing to put your heart into it."
- Cowan qualified for Canadian national swimming competitions and won numerous medals. In August, 2001 she qualified for Canada Games where she won two silver medals in the 50 meter backstroke and 100 meter breaststroke and set a new Canadian record in the 100m breaststroke.
- When she heard about Vicki Keith's marathon swims across Lake Ontario at the age of 8, she decided that she wanted to swim her own marathon. She attended Variety Village, a fitness center for children and adults with disabilities in Toronto. She introduced herself to Keith and told her of her dream. At the age of 8 1/2 Cowen began swimming under Keith's tutelage with a para swimming classes of S4 SB3 SM4.