The mother and half-sister of a teenage girl allegedly put her in bed and went to watch TV when they knew she had taken a heroin overdose, a court heard.
Carly Townsend, 16, died in the night at their Carmarthenshire home in May.
Andrea Townsend, 45, and Gemma Evans, 25, of Pwll, Llanelli, deny manslaughter through gross negligence.
The experienced drug users put her in the recovery position in bed and went to watch Emmerdale rather than call an ambulance, Swansea Crown Court heard.
It was claimed that during the day Carly, who had been taking heroin for two years, had injected the class A drug.
Paul Thomas QC, prosecuting, said she had been complaining about the symptoms of an overdose, including having a hot head and drifting in and out of consciousness.