I am going to bring this up again in response to your post....
I almost exclusively referred to my children as "the baby" or "my baby" when they were infants and toddlers. I rarely used their given names when discussing them with other people. And I can assure you that I was not "distant" from my children then, and I am not distant from them now. In fact, I am very close to all my children. And I still refer to them as "daughter, or "son" when talking about them to other people.
I don't think anyone can say with any degree of certainty that DB's choice of words means anything. If one of my children had been missing as an infant, I would be just as likely to say "the baby" as DB is, and I can also assure you that I would never harm a hair on my children's heads.
DB may have played a role in what happened to Baby Lisa, or she may be completely innocent. But I don't think anyone can tell anything at all from what she calls her child in public, because I would do the same thing.
DB is clearly distraught about her baby. That's really all we know for sure right now.