A court heard Tina Mason hid the drug in her bra before handing it over to him in the visiting area of HMP Wealstun, Wetherby.
Philip Adams, prosecuting, said Mason's son was an inmate at the jail at the time of the offence.
Mason went to visit him with two other adults and a child on February 26 this year.
Leeds spice: Major effects the mind-altering drug can have on users and how long it takes to feel themMr Adams said: "Towards the end of the visit a prison officer saw the defendant drop an item on to the table and begin fumbling with it before leaving the visiting area.
"It was a tightly folded piece of paper which the officer thought might have been soaked in a controlled substance."
Mason was stopped by officers and police were called.
CCTV footage of the visiting area was reviewed.
Mason was seen to put her hand down her top and remove the item from the top of her bra before putting on the table.
The piece of paper was found to have been soaked in synthetic cannabis.
READ: Driver 'foaming at the mouth and laughing' while crashing car during police chase - Leeds Crown CourtMason, 51, of Calverley Lane, Bramley, pleaded guilty to taking a prohibited article into prison.
Jessica Strangle, mitigating, said Mason had not committed the offence for financial gain.
Miss Strange said Mason had health problems and had responsibilities for the care of her granddaughter.
Mason was given a three-month prison sentence, suspended for 12 months.
She was also made the subject of a curfew for six months, between 8pm and 6am each day.
Judge Christopher Batty told Mason: "I have no doubt that this was motivated by your love and loyalty to your son and to make his life just a little bit more bearable at a time when you were worried about him being in custody.
"Ordinarily you would go to prison.
"What saves you is your granddaughter and your health."