An Adelaide coroner will resume an inquest into the death of a four-year-old girl, forced to endure chronic neglect at the hands of her drug-using teenage mother.

Chloe Valentine died of massive head injuries after being forced to ride a motorbike that repeatedly crashed over a three-day period in the backyard of her Adelaide home in January 2012.

Witnesses revealed Chloe was never removed from her mother, Ashlee Polkinghorne, despite a child protection agency receiving 20 abuse notifications during her short life.