Your last paragraph is the one way I could envision the SM being involved in a cover-up. Perhaps she had some Xanax or some other prescription for herself and gave some to Karlie. Maybe she even looked up to see if it had a reaction with pot. Kaylie either had a bad reaction or passed due to whatever the joint was laced with and the SM panicked thinking she was responsible. I still think we will find Kaylie somewhere for better or worse and we will have our answer.