Jennifer Crumbley tearfully took the stand at her involuntary manslaughter trial on Thursday, 1 February.
The mother of teenage school shooter Ethan Crumbley wiped away tears as the court showed photos of her son.
Ms Crumbley faces four counts of involuntary manslaughter, to which she has pleaded not guilty.
Her husband, James Crumbley, is being tried separately in March.
The pair are the first parents to be charged for their alleged role in a US mass school shooting.
Ms Crumbley appeared emotional while on the stand after she looked at photos of her son, including a picture of him holding his pet chinchilla.