She won two silver medals and one bronze medal at the Olympic Games and World Championships, all with the Norwegian relay. Dahlmo's best result in an individual Olympic race was eighth in the 30-kilometer run in 1988. Her best individual results in a world championship race were fifth place in 1987 over 10 kilometers and in 1991 over 5 kilometers.
In the cross-country world cup , Dahlmo won one race between 1986 and 1989. In the 1985/86 season she reached second place in the overall standings, she was a single point behind the Finnish World Cup winner Marjo Matikainen . 1986/87 Dahlmo was third overall.