Blake Barrass, aged 14 and Tristan Barrass, 13, died in Sheffield last Friday.
They were among six children taken to hospital after emergency services were called to a house in Gregg House Road, Shiregreen, at 7.30am that day.
The two teenage boys later died and a murder inquiry was launched.
South Yorkshire Police confirmed this morning that post mortem examinations have been carried out but the results have not been disclosed for ‘operational reasons’.
Sarah Barrass, aged 34, of Gregg House Road, Shiregreen and 37-year-old Brandon Machin, of no fixed abode, are both due to appear at Sheffield Crown Court today accused of murder.
They were remanded in custody after appearing before Sheffield magistrates yesterday.
Barrass is also accused of three counts of attempted murder against two other children.
Those children – as well as two other youngsters – cannot be named for legal reasons.
A High Court injunction banning their identification covers social media comments, photographs or anything else that could lead to their identification.
South Yorkshire Police has warned that those who name the youngsters could be charged with contempt of court.
More to follow.