In some older stories she is notably absent, but in other stories, such as "De Botte Botaknol" (1980-1981), "De Kattige Kat" (1984-1985), "De Flierende Fluiter" (2004-2005), "De Hippe Heksen" (1983) and "De Europummel" (2001-2002) she plays a central role.
While normally being a housewife Sidonia sometimes performs jobs.