She was a member of the Lambert Puppet Theatre in Monkstown, County Dublin.
From childhood, Lambert was a puppeteer with the family's Lambert Puppet Theatre, which was founded in 1972, and on their first television show, Wanderly Wagon.
[2][3] Lambert took over from her sister Miriam as the puppeteer and voice of Bosco in 1981.
[2][4] 2019 marked 40 years of Lambert's Bosco tours.
[5][6] Lambert was in a relationship with Michael Monaghan, a former RTÉ producer and director, until his death in 2009.