The children are 10-months and 3-years old.
Investigators say the incident happened November 29 at the family's home in the city's Portage Park neighborhood, following an argument with the father of one of the children. He called police, who took them to the hospital.
Vera was charged Tuesday night after FBI crime lab tests confirmed the substance given to her children was poisonous.
Both children are now in protective custody.
The Associated Press contributed to this report.