4meSM
Bluelighter
It's very difficult to provide a comprehensive rational explanation for stuff related to the human psyche. There's probably multiple causes to that sort of stuff. Plus the human brain is pretty much the most complex organ/object in the known universe, it's hard to understand why people have certain experiences.I also remember when i was in my twenties and dating this one Girl who had a 3yr old girl, Some nights she (the 3yr old) would wake up screaming and crying from nightmares and we didn't know why. One night when this happened and she couldnt fall a sleep and seeing as (my girl at that time) needed her sleep for work, the one specific night her little girl freaked out again i offered to lay with her in her bed till she fell asleep and keep her safe. She fell asleep and so did i after a while and it was then that i woke up from something pushing me down in bed and i couldn't talk or say anything, this went on for only a few seconds but as soon as i could move i pict her girl up and quickly moved to our bedroom and slept with her between us for the rest of the night or early morning hours. I explained this to her the next morning and told her that this flat she is staying in is not on, something is wrong. She moved out end of the month to a knew place and it never happened again to her daughter or me for that matter, so even till today that haunts me in away as i just can't find any rational explanation.
Children are very susceptible and they are constantly absorbing information. If the parent is stressed (or angry, or going through something) that can often have an impact on the child's mental state. The bond between parent and child is very powerful.
I obviously can't provide a true explaination but the behavior you described appears to be correlated with separation anxiety. Seems like moving to another house had a positive impact on the bond between the mother and her child and possibly on their sleep routine as well. Even simple stuff like being more aware of what the child is experiencing can make a big difference.
You might find this interesting: https://pubmed.ncbi.nlm.nih.gov/17438080/