She had roles in British TV series such as Danger Man, The Saint, The Baron, The Prisoner and The Avengers where, having appeared in the penultimate episode of the 1967 series, she was considered to replace a departing Diana Rigg. The role went to Linda Thorson instead. She also appeared in Who Killed Cock Robin? (Randall and Hopkirk Deceased) in 1969. In 1971 she played Anne Hepton in the second series of Hadleigh who became the romantic interest of the lead character.
Merrow returned to England after living for years in the US to run a family business in the 1990's. In 2006 she took part in an event at Portmerion in North Wales to celebrate The Prisoner .
