A man and woman arrested on Friday 24 May at an address in Shiregreen have now each been charged with two counts of murder
The woman has also been charged with three counts of attempted murder .
READ MORE: Man and woman charged in relation to deaths of teenage boys
Both will appear at Sheffield Magistrates Court tomorrow (May 27).
The two cannot be named for legal reasons.
READ MORE: Tributes paid to teenage boys who died after major incident
The two teenagers aged 13 and 14 were among six children taken to hospital after emergency services attended a property on Gregg House Road, Shiregreen, Sheffield, at around 7.30am on May 24.
Four other children, aged 11, 10, three and seven months, were also taken to hospital.
A South Yorkshire Police spokesperson said family members have been informed and are receiving support from specially trained officers.
The cause of death has not yet been established and a post-mortem examination will be carried out.