Having expressed an interest in acting since the age of five, she applied to and was accepted by the Central School of Speech and Drama in London but because she was too young, her place was deferred for a year.

Ellis's first television appearance in 1978 was a small role in the BBC's children's programme Jackanory Playhouse, followed by a bit part credited as Marge's Friend in The Sweeney episode Hard Men.

[5] During her four-year stint, she co-presented with Simon Groom, Sarah Greene, Peter Duncan, Michael Sundin, Mark Curry and Caron Keating.

[7] After leaving Blue Peter Ellis scaled back her presenting commitments in order to spend time bringing up her family.

During this period she presented the BBC's Open Air programme, wrote a book entitled How to Get Married Without Divorcing Your Family with her friend and ex Blue Peter co-host Caron Keating in 1994, and provided voiceovers for numerous advertisements.

She also presented the Daz Challenge in the television advertisements for three years and occasionally appeared as a co-presenter on Danny Baker's BBC Radio 1 show.

[9] In May 2008, she appeared naked in a magazine in support of PETA[10] and in June of the same year she won The Weakest Link Blue Peter celebrity charity special.

She was the voice of numerous Mexican gerbils in El Nombre, and has appeared on BBC's Antiques Road Trip with daughter Sophie; Bargain Hunt and Cash in the Attic.

Ellis won, beating singer Tony Christie and actress Susie Amy into joint second place, with musician and actor Goldie bringing up the rear.

In January 2012 Ellis returned to her first love of acting by starring in a production of Alan Bennett's comedy play Green Forms for a week at the Tabard Theatre in Chiswick in order to raise money for Maggie's Centres.

[14] In 2018 Ellis wrote an opinion piece in The Guardian newspaper in which she characterised Blue Peter as offering "...a view of a world worth growing up in".