She is known for her television roles, including Lou Kelly in Prisoner (1984–1986), Debbie in The Flying Doctors (1988–1990), and 2012-2017 Heather Looby in House Husbands.
Born in Melbourne, Siversen began acting as a child after her parents sent her to dance and drama classes to help her overcome her shyness.
[1][failed verification] Siversen was to study law, but decided to stick with acting after attending a Career Day at university.
Siversen had done several bit-parts in the series and at the time the character of Lou was devised, and had been a regular extra for several months, playing one of the prisoners.
Her other TV credits include The Flying Doctors, Halifax f.p., 'Sugar and Spice, BackBerner, MDA, All Saints, Janus, Rush, Special Squad and House Husbands.