Oddly, I don't think AD was prostituting herself.
Most definitely not in the streetwalking sense, MOO.
I think she was your basic drug addict, selling what she needed to to get drugs, and taking fronts from dealers until payday. When payday stopped coming, someone suggested her daughter as a payment, and she took the opportunity, rather than have to work it off herself.
If she had been prostituting herself, no reason to prostitute Shaniya...
This is based on the personal fact that drugs usually eclipse shame. With that in mind, it seems to me that if AD were hooking, she just would have gone on hooking, and never offered Shaniya at all. There would have been no thoughts of stopping because she didn't like it, those thoughts aren't there for an addict. Addicts want drugs, and once they've sold themselves for it a few times, the thought processes are linked. They like drugs, sex gets them drugs...why stop?
(I work outreach with local prostitutes and I have asked some of them about this case. Each and every one of them is appalled and shocked and really wants a piece of AD.)