Patience Monkei-Khame, 33, was searched at the airport when authorities noticed there was no baby in the pram, the Saturday Star said.
The contraband was found secreted in the hollow metal frame of the perambulator.
Malawian police spokesperson, Peter Botha, said Monkei-Khame arrived in the country from Brazil and was due to fly on to OR Tambo International Airport.
He said she confessed and claimed a gang had offered her R30 000 to smuggle the drugs into South Africa.
Last month another South African, Nolubabalo Nobanda was caught at a Bangkok airport with one-and-a- half kilograms of cocaine concealed in her dreadlocks.
In December, Janice Linden was put to death in China for drug smuggling.