An eyewitness said the girl, who managed the brother’s car wash business, was fond of returning late from work, an attitude the brother frowned at.
He said on the fateful day, the brother descended on the girl as soon as she returned home, leaving her with minor injuries and her eye glasses damaged.
Subsequently, before leaving the house, the brother instructed the girl to sprinkle the poisonous substance in the house against mosquitoes, Daily Trust reports.
"After sprinkling the substance in the rooms, she drank the remaining quantity in the container after dropping a suicide note," he added.
The girl was rescued by neighbours who overheard her screaming and quickly rushed her to the Kubwa General Hospital.