Kamla Devi, 65, was arrested last evening when she had gone to visit her son Sudhir after jail staff found that she had concealed about 50 grams of charas in a packet attached to the sole of one of her sandals.
On being questioned, she claimed that her son was addicted and she had supplied him with drugs in jail many times earlier, they said.
She has been handed over to Kotwali police, who have filed a case under the Narcotics Drugs and Psychotropic Substances (NDPS) Act.