I agree with you in terms of the bolded part. I think AD never expected for Shaniya to die. I think she brought her into the living room or into the front yard and accepted something ungodly would happen to her, but I believe she expected her to be back within a couple hours.
I also don't think she sold Shaniya to MAM or anyone else, at least in the strictest sense. I think she was woefully behind on a drug debt and MAM "suggested" Shaniya as payment. Suggestion might have involved threats to torture or kill AD or her son and Shaniya was relatively expendable. She hadn't had time to really bond. I think I might be in the minority by thinking that this decision was not an easy one for AD, but of course that doesn't excuse it by any means. I just think AD was a drug-addled mess who had quite a bit of pressure applied. She differs from the rest of us in that giving up Shaniya was actually something she would do instead of running screaming to the cops or a neighbor or BL or anyone else.
I don't think this was a routine thing, and I don't think AD shopped her out around town. After all, as much as we immerse ourselves in the cases here, I'm not sure that AD or MAM or anyone else had the connections or the marketing skills to enslave Shaniya. Did they even have internet access? I think AD was a monster who got caught in her first foray into this "business" and MAM might have raped kids before. I honestly think both of them were drugged out of their minds when they hatched this plan and that AD has a monstrous hell waiting for her when her mind clears. I wish pain and misery and eternal suffering on both of them.
I just don't think this was an enterprise. I think it was two sick, drugged-up freaks. One in jam, one a depraved pedo. My gut is that the deal was made in the early morning hours and Shaniya was dead by 8am that day. I refuse to give them credit for anything more organized than that.