A state report has shed light on a prior investigation involving the mother of two young sisters who drowned in their family's backyard pool. The incident is particularly disturbing as the girls had cocaine in their systems at the time of their death. Child Protective Services had looked into a drug allegation against the mother nearly two years before the tragic event.

Further details about the investigation and its outcome are available from the source. For more information on this developing story, readers can refer to the original report from ABC13 Houston, which provides additional context and background on the incident.