The Liver Birds and Series 1 starred Pauline Collins as Dawn and Polly James as Beryl Hennessey. In Series 2, Nerys Hughes debuted as Sandra Hutchinson, replacing Dawn for the rest of the programme's run. The Beryl-and-Sandra pairing is generally regarded as the programme's best period. Beryl was the more 'common' one, while Sandra was soft-spoken and more refined, due to the influence of her snobbish, overbearing mother (Mollie Sugden). Carla Lane drew on her own mother for the character – "Mrs Hutchinson, I think she was my mother. I'm sure she was my mother". Beryl's 'common' mother (the Hennesseys live in Bootle,
Polly (Doctor Who) in case it would be confused with earlier companion Barbara Wright. In "The Faceless Ones", a double of Polly is named Michelle Leuppi; an apparent mishearing of this and misinterpretation of the context led to some reference works giving Polly the last name of "Lopez". Anneke Wills suggested the name "Bettingham-Smith", after one of her friends. In the Virgin Missing Adventures novel "Invasion of the Cat-People" by Gary Russell, Wright is expressly given as Polly's last name, as it was supposedly given in Gerry Davis's character breakdown and audition script sample when, as story editor, he and producer Innes Lloyd