The woman is accused of unlawfully delivering a controlled substance to a minor and manufacturing marijuana, according to reports.
It's believed the boy inhaled smoke from the drug from a bong.
The alleged crime happened in Centralia in Washington state, USA.
Police arrested the 24-year-old woman and a 25-year-old man, the boy's father.
Officers found 40 marijuana plants and several firearms during the search, the release said. The man is accused of three counts of unlawful possession of a firearm and manufacturing marijuana.
The woman is accused of unlawfully delivering a controlled substance to a minor and manufacturing marijuana.
The boy, as well as another child, are now in the custody of Child Protective Services.
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