In 2013, Jaggi was made as a Commandeur of the Ordre national du Mérite.

[1] Jaggi joined the Social Democratic Party of Switzerland in 1972, a year after Swiss women obtained the right to vote in federal elections during a 1971 referendum.

She was elected to the Lausanne Municipal Council in 1981 and headed the city's finance department.

[4] In 1989, she was re-elected to the same office and, in November of that year, was elected as the first woman, and third socialist, mayor of Lausanne.

On 21 February 2013, Jaggi was decorated as a Commandeur of the Ordre national du Mérite in a ceremony at the French Embassy in Bern.