Holly Strawbridge, 34, allegedly supplied 15-year-old Tyler Peck and a friend with drink and morphine in the kitchen of the family home in Salcombe, Devon.
They are also accused of sniffing aerosols together in February – before Tyler was found dead hours later.
Strawbridge went on trial at Plymouth Crown Court this week but the case was halted when her solicitor fell ill.
Judge Paul Darlow has now discharged the jury after he said the court no longer had time to hear the full trial – scheduled to last between five and seven days.
Several young witnesses, including the 15-year-old friend allegedly involved in the alleged drugs binge, were due to give evidence.
A new trial in front of a fresh jury has been listed for December 3.
Strawbridge has pleaded not guilty to supplying Tyler and another boy with the Class A drug morphine at the home between January 31 and February 3.
The defendant has also denied two further charges of cruelty towards the two boys between the same dates.