Pam Annette Bickerton, 73, faced a pre-sentencing hearing at Adelaide Magistrates Court last week, after admitting to a count of supplying or administering a controlled drug to a child, court documents showed.
She had prepared the drug-laced butter to help deal with a sleeping disorder, the April 19 court hearing heard, according to a report in the Adelaide Advertiser.
According to AFP, the ****ager, who has not been identified, woke up the great-grandmother to ask to use the cannabis butter for some muffins, the court was reportedly told.
"Still in a state of tiredness and unfortunately ... she said 'go for it - just make sure that you clean up afterwards'," her lawyer was quoted as saying.
Bickerton was "extremely remorseful", the court heard.
Magistrate Justin Wickens said it was "somewhat concerning" that the elderly defendant knew the **** would share the muffins with friends.
"As it turns out, it went to school, which is unfortunate but that is not something that was in your client's mind at the time," he was quoted as saying.
Bickerton is due back in court for sentencing on May 4.