Claire Johnson, 41, failed to call an ambulance when daughter Natasha, 21, collapsed after taking heroin in 2013.
A medical expert told Leeds Crown Court had Johnson sought assistance, Natasha's chances of survival would have been "extremely high".
Johnson, of Market Way, Scarborough, was jailed after she pleaded guilty to manslaughter by gross negligence.
Daniel Kedge, 41, who gave Natasha the heroin, was jailed for 16 months after being found guilty of supplying Class A drugs.
Kedge, of Carlton Terrace, Halifax, was cleared of manslaughter by gross negligence.
The court heard Natasha, who was not a heroin addict, had collapsed and begun struggling for breath immediately after injecting the drugs in May 2013.
Rather than call for help, Johnson put her daughter in the recovery position and went to bed.
The following day she noticed Natasha's body was cold and covered her with a towel but later realised she was dead.
Johnson has never given a proper explanation as to why she didn't get help, police said.
Det Sgt Jonathan Sygrove said: "Claire Johnson had a duty of care to Natasha which she quite clearly breached when she failed to call an ambulance for her when she collapsed after taking heroin.
"This was a tragic end to a young life which could most probably have been avoided if the person who was with Natasha in her hour of need had acted in a correct and responsible manner."
A mother who left her daughter to die from a drug overdose has been jailed for two years and eight months.