No offence intended, but at times like this I think people tend to look for a simple answer that would have saved the child/victim. So there are commonalities here that are present in other cases, social services, drugs, slew of unsavory boyfriends, lack of close (good) family and friends.
How many other women (or men) are bringing up children under similar circumstances and don't actually physically abuse the child, let alone end up murdering them? I think the answer is a lot, and the children grow up, some in better state than others. I don't think there are black and white answers to be had. Some might be okay with visits from social services, maybe occasional breaks for foster care and rehab. Allowing them to have welfare might keep some of those mothers from turning to prostitution or worse for money, and whether she was spending money on drugs or cigarettes, Bella did look like she was reasonably well-dressed and cared for...at least on the surface, or at least during better times.
For every child who ends up adopted to a good family, I fear there are half a dozen others who go through the foster care and 'orphanage' route, in and out of either/both of those and occasionally back to family. There's a high tendency for them to have problems, early sex, drugs, teen babies that they might not be able to care for very well themselves.
I once spoke to a teen mom who'd been through what I just said in the last paragraph. She had a sister who'd had a baby and the girl I spoke to told me that she wanted to adopt her niece but the rules said that if she did so she would have to cut contact with the biological mother...move to another town lose her contacts with other family members. Is this possibly what happened to Rachelle's mother when she adopted one of Rachelle's children? Is this why there was no contact for 14 years, since the date of that adoption?
And these comments about how many people would have loved to adopt Bella...the person was correct, imho, who said if anyone knew what was about to happen to her, yes of course anyone would take her in. Anyone would wish to give a child like that a better life. But let's not play the blame game here, lots of those people with those feelings are not in a situation where they can foster or adopt. Let's not point fingers at those who can't or haven't. Let's just encourage those who maybe could and just need a prod in the right direction to get them onto the foster or adoption lists (and adoption can be very difficult with some very tough rules regarding age, health, etc). If someone does have the love to give, the time, a spare room, etc, then now's as good a time as any to offer what you can to a child in need, baby or older child. Realistically, though, many of those children are going to be very difficult to parent, just due to what they've seen and experienced in their lives, and not everyone has the patience and temperament for that.
I think that what's going into the media now is likely a bit of a confused mess, reporters contacting anyone and everything just to get some kind of story to print, and there are often a lot of errors at this point of a case. I expect the charges given now are preliminary to a lot more investigation, and I hope both of the arrested get hefty sentences. I don't trust anything Rachelle says, she could easily have had a fight with MM and blamed him out of spite and I suspect her story, true or not, is more about getting pity for herself. Neither of those people called an ambulance, neither bothered to report the person who did it, whatever the truth is, I consider them both complicit and vile.