Could Sudden Demise Be Due To Over Dosage Of Drugs?

My sister just died couple months ago. She was drinking beer and xanax. She was found on her stomach with blood coming from her mouth. She was found hour or so after estimated time of death and seen right before then as well. So far, all her organs are fine considering her alcoholism and prescription drug abuse. Could she have overdosed or what does it sound like to u ? We don t know yet. Thank u.