The "foam cone" around her nose is indicative of being in a prone position at the time of death due to suffocation, as shown here: https://www.researchgate.net/publication/221745245_Foam_Cone_exuding_from_the_mouth_and_nostrils_following_heroin_overdose

He found her laying on her stomach, and told his roommate he rolled her onto her back, involving himself in her care.