I watched one of the news clips where the GF and the dad were hugging, where she told the newsman she put the kids to bed at 8pm - then she looked at the dad with a look....... Like she wasn't telling the truth but telling what he wanted to hear. It was the kind of look a naughty child would give after doing something wrong.
There's a report of her two young cousins being at the house. Then there was the A/C guy, and now her brother and his friends. Seems like a lot of traffic for the GF to pay attention to, plus the little children. That's if all the visiting reports are accurate. Could she have misplaced the child earlier and not known what to do about it?
I also babysit as a teen in the 1960s
but I stayed with my brother who was 10 years younger, and then later with lil bro and my sister who was born when I was 16. I was well-schooled in child care and knew I would have been killed if anything went wrong on my account. I was responsible and things were different, and I wasn't doing the drug thing or the sex thing. Rather dull, I'd say. At 18 or 19, I sat for others, and for my friends who began having kids long before I did.
I just think the GF isn't responsible enough, nor wise enough to take care of children so young. She seems extremely childlike to me, a child herself, who has found her way into a dangerous adult world. So the assumptions that negligence of some sort paved the way for the abduction could very possibly be correct. Someone could have left the door unlocked while all those people were going in and out, or someone else came in while all the people were otherwise occupied with chatting and whatnot. By the time the child was noticed missing, the GF didn't think to call the police or was too afraid of the consequences, or needed time to cook up an alibi.