Hmmm...I'm guessing, an enabler will continue as long as there is personal gain (power, position, love, money; whatever the particular enabler placed in high value)
I think the relationship between KC and CA was more complicated than that. KC was the controlling force in her family, she knew it and CA knew it. CA didn't so much enable KC, as CA had no idea how to deal with KC. Exchanging control for peace in the household (or at least the appearance of peace) was CA giving up, more then giving in.
This doesn't work, will never work, when dealing with a KC. She will continue to wreck havoc, until there is nothing left. CA had finally realized she was out of her league when she went to the counselor who advised kicking KC to the curb and taking custody of Caylee.
I don't remember hearing when CA started seeing the therapist but I'll bet the timing is important. It wouldn't surprise me if therapy started around March. Changing CA was not something that happened in 1 visit. Just like everything else, it was a process.
CA taking charge and taking custody was the last straw, Caylee was getting the love that belonged to her and KC wasn't standing for that any longer. It was bad enough Caylee took so much time and effort away from KC's real interests, she was not allowing Caylee to have her position in the family as the reigning princess too. The only way for KC to insure her place in the family was to dispose of Caylee.
Think about some of the families you knew when you were growing up, there's always someone who will stand out as having the perfectly kept yard, the perfect pet, the perfectly (over kept) children who never appeared to get dirty, hair always in place, nails manicured, shoes shined. These households were run by a CA. How many of these families ever "lost" a child or grandchild the way KC "lost" Caylee?
To blame CA's personality type for KC's evil doing absolves KC of responsibility.