Elaine Clarke, 49, admitted the gross negligent manslaughter of Debbie Leitch, 24, who had Down's Syndrome and died from severe emaciation and neglect.
A post-mortem examination found she also had an extensive scabies skin infection.
Debbie's emaciated body was discovered inside a house in Blackpool, by emergency services on August 29, 2019.
Six people were arrested in connection with Debbie's death.
Clarke was charged with gross negligent manslaughter.
Her former partner Robert Bruce, 45, from Rothwell in Leeds, was charged with allowing or causing the death of a vulnerable adult.
The charge against him was later dropped.
Clarke previously pleaded not guilty to killing her vulnerable daughter, but changed her plea just 10 days before the case was due to go to trial.
She will be sentenced on February 7.
Judge Amanda Justice Yip told her: "You are well aware of the inevitable outcome that you will be going to prison, and I think the time has come that I am going to remand you to prison to make sure you are here on time on the next occasion.
She added: "As far as (Mr Bruce) is concerned, a not guilty verdict has been entered and (he) will be released."