Gaby Schley and the West German female field hockey team won the silver medal at the 1984 Los Angeles Olympics round-robin tournament, finishing with six points. As Gaby Schöwe she was also on the team that finished fifth at Seoul four years later, after a 4-2 win against Canada in the classification round. She was also the European Indoor Champion in 1985 and 1987 and won the bronze medal at the 1984 Europeans. She added a silver medal at the 1986 Worlds, and a bronze at the 1987 Europeans. She won 108 international caps (including 14 indoor) between 1982-88.
Domestically, she played with Uhlenhorster HC Hamburg and Kölner THC Blau-Weiss. In 1986 and 1987 she helped Köln win the German Championship and in 1985 the Indoor title. Schley-Schöwe later became a graduated sports teacher and chief youth coach at DSC 99 Düsseldorf.