Troopers stopped 22 year-old Radiance Hagler-Grant for swerving left of center several times in Knox County.
Troopers say they smelled a strong odor of burnt marijuana when they approached the woman's car.
Her 4 year-old son was in the back seat.
A k-9 unit alerted troopers to the presenece of narcotics and a search found a small amount of pot and drug paraphernalia.
Hagler-Grant faces four misdemeanor charges.
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