[2] She won two bronze medals in tennis at the 1900 Summer Olympics in Paris, in the women's singles and the mixed doubles with Great Britain's Archibald Warden.

At least since 1894 she played in singles, doubles and mixed tournaments in Cisleithania and Germany for the Prague Lawn Tennis Club.

In 1900, Rosenbaum took part in the second Summer Olympics in Paris as a private individual from Prague at her own expense for travel, accommodation and entry fees.

In the individual tennis competition, she lost in the semifinals to eventual silver medalist Yvonne Prévost in straight sets 6–1, 6–1.

Hedwig Rosenbaum had been managing director and board member of the Club of German Female Artists in Prague (Klub deutscher Künstlerinnen in Prag) since it was founded in 1905.