Kosmala was introduced to wheelchair sport by a patient at the Royal Adelaide Hospital, a few months before starting work at the Adelaide Botanic Garden. She first competed nationally at the 1966 National Wheelchair Games in Brisbane. She competed in foil fencing, swimming, wheelchair racing, field events, and archery. In a 2011 interview, she said that the organiser who picked the team for the 1968 Tel Aviv Paralympics forgot to include her, so she worked as a secretary at the games instead. She won two gold medals in archery and foil fencing, a silver medal in the pentathlon, and four bronze medals in swimming and wheelchair racing events at the 1970 Commonwealth Paraplegic Games in Edinburgh, in her first international event. She initially had to raise all her own money for the games, but after a radio interview and a newspaper article about her plight, John Eustice Motors gave her a cheque with all the money required for the games.