This interview (though I have not watched it) gives us the information to know that the mother is involved with the missing baby. She has "moved on" to understanding that she needs to create a defense strategy for herself and knows she will be a suspect of a crime because she knows full well that this baby isn't going to be found.
Unfortunately the simplest answer is most likely what happened. She may have even stumbled out of the house and buried the baby somewhere. My mother was a drunk to us kids and one night she woke all of us up and walked about 2 miles up the road to where she had seen a dead squirrel on the way home and made us put it in a box and bring it home to be buried.
She also used to do things like wander around naked at 4 am. No one in the neighborhood ever saw her do this. As kids we'd be mortified. One night she had my brothers and sisters lay down in the street to see if they could hear cars coming by the rumbling of the street the way Native Americans used to with horses. My sibs were 7-8 years old and the cops found them and DID NOT ARREST MY MOTHER, just told them all to go home. So the idea that someone would have noticed something isn't true.
She also was extremely violent and dangerous. One time she threw my brothers pet hamster out the attic window because he didn't clean the cage, another time she tried to throw me out the same window. She set curtains on fire to teach us a lesson once. The worse thing she ever did was to lock herself in a room with my baby brother and tell us she had a butcher knife and was going to cut his arms off if we didn't stay home from school and baby sit him.
Drinking from 7 pm onward can throw you for a loop. I drink and my kids are older and i'll go out and drink and leave my kids with their father. I've never had a black out. This woman didn't drink one box of wine. She probably had something else in the house that she started in on. My mother would black out, and deny everything. But no matter how smashed I've ever gotten I've only thrown up as a young person. If you are blacking out, you are a hard core drinker. This might also explain her change in behavior, she can't drink now and might be going through DTs.
The lights on, cell phones gone and front door open, suggest to me that she killed the baby by accident and just stumbled out and buried her nearby the home.
The other thing that points to guilt to me is that they didn't start mad calling the cell phones that were taken in order to get them pinged.
Wouldn't you do that?
The door open and lights on are a very familiar scene to a drunk who blacks out, so is food dropped on the kitchen floor, clothes strewn about, phone calls made in the middle of the night etc.