I think the other possibility is that the women blamed the first 3 because they “had to” abuse them and got the second 3 to fulfill their family fantasy.
The "family fantasy" is a reasonable theory/ explanation.
I tend to think the root is more based on addiction. This is all my own opinion and observations. I see parallels in cases where addiction seems to be a recurring theme.
I think it's quite possible these woman were addicts, not in the drug sense but in another sense. I think each adoption fulfilled them feelings of overwhelming "empowerment", "uniqueness", "heroism" in "saving" these lives of underprivileged/ family-deprived children.
People can get hooked on a type of feeling just the same as a drug. Drug addicts get hooked
because of the "feeling" the drug gives them.
It's my opinion that women were addicted to the feeling they got from adoptions. And when they weren't adopting, they were taking these children to progressive rallies and protests in order to "make a difference", "better the future", "equality", etc.... The protests give them the SAME feelings of "empowerment", "uniqueness", and "heroism" as did the adoptions.
People who are addicted to a feeling continue to do things that give them the desired feeling. And when the feeling feeling fades, the more they long for it. Hence, adoption around # 2, IMO. Just like drug addicts, they continue to do things even when the it becomes harder and harder to get the feeling. It becomes harder and harder to maintain and eventually it implodes as they hit rock bottom.
To me the second adoption was more powerful than the first because they were undoubtedly already having trouble/struggles with the first 3 kids, but in their eyes their level of heroism was even higher because their situation harder than the first time, because they already had 3 kids. "Saving" even more lives on top of those they are already "saving".
I see similar addiction patterns in the Turpin case. The addiction is different but still an addiction to a type of feeling.