I don't think it was suicide either. If she was going to do that she probably would have done so months ago when her son died. And I don't think she'd want to leave her newborn without its mother. She probably OD'd on the same thing Howard K. Stern gave her son.
I could see a suicide IF she gave her son the accidental overdose, but her death does not read suicide at all. She loved attention and she didn't mind fighting for what she wanted.