A Sydney court has heard a great-grandmother dealt marijuana because her daughter was battling terminal cancer.

Barbara Patricia Stiff has faced Waverley Local Court charged with dealing cannabis from her Malabar home in Sydney's south-east.

The 78-year-old was arrested in June 2013 when police found 67 grams of cannabis, scales and other drug paraphernalia in her home.

Ms Stiff pleaded guilty to supplying a prohibited drug and dealing in the proceeds of crime.

The court heard she is the full-time carer for her physically and intellectually disabled daughter.

In sentencing submissions to Magistrate Robbie Williams, her lawyer told the court she became involved with dealing drugs while caring for another daughter who died of terminal cancer nine months ago.

Her daughter and friends purchased the marijuana for pain relief and distributed it among themselves.

Magistrate Williams has handed Ms Stiff two suspended sentences, of four months and three months.

The magistrate took her age and role as a carer into account.

Outside court, Ms Stiff's solicitor William Barber said his client is glad she can move on.

"She's had a very difficult time," he said.

"She's greatly relieved this is over and she would like to go quietly away and look after her daughter."