She also played a young Lou Beale in the EastEnders special CivvyStreet, a spin-off that was filmed in 1988 but set in 1942.
Meagher is perhaps best known in Britain for the role of Ruth Beckett in the 1984 BBC nuclear war drama Threads.
She also later appeared in a film outlining the risks attached to nuclear power; Chernobyl: The Final Warning.
Since then she has had many television and film roles including playing Inspector Murchison in Heartbeat, Grace Poole in the 2006 BBC adaptation of Wide Sargasso Sea, as well as smaller roles in Dalziel and Pascoe, Carrie's War, Down to Earth, Doctors, The Bill, Bad Girls, Silent Witness, Sharpe, and Father Brown.
She appeared in the 2007 run of Equus in London's Gielgud Theatre, portraying the nurse and was also understudy for Jenny Agutter and Gabrielle Reidy's roles.