A Denver grandmother who recently took her own life was under investigation for giving her 3-year-old grandson a marijuana cookie.

Family members say 44-year-old Erin Marcove gave the toddler at least one peanut butter cookie made with cannabis butter on Dec. 4. The next day, she had trouble rousing the boy and called an ambulance.

A week later, relatives told KMGH-TV the grandmother took her own life. Marcove was an advocate for medical marijuana and had used the drug for chronic back pain most of her life.

Police seized a jar of cannabis butter at her home, and a police report showed the little boy had the drug in his system when he was taken to the hospital. The toddler has fully recovered.