In 1811, Skjöldenbland reported, that Gustav Åbergsson had gone on a study trip to Paris with her; "An actor of the higher comedy, mr Åbergsson, had in the company of his mistress, an excellent actress in her own right, who were later to become his wife, went to Paris to develop himself in his profession." At his return, he brought the play Cendrillon, and demanded that the main part be given to her.
Westerdahl was a dramatic actress, but she also occasionally participated in some opera performances, such as when she replaced Elisabeth Frösslind in Cendrillon.
Her other roles at the ROH in the 2010/11 season included Second Lady in Die Zauberflöte conducted by Sir Colin Davis, and Dorothée in Cendrillon.
In 2000 he was engaged as a Bass at the Thater Lübeck where he sang Procida (I vespri siciliani), Pandolph (Cendrillon), Orest (Elektra) and Ramfis (Aida).
Her discography includes Henry Purcell's King Arthur (conducted by William Christie, 1995) and Dido and Æneas (led by Martin Pearlman, 1996), as well as Pauline Viardot's Cendrillon (2000).