It probably is a combination of everything. First, her extending the nursing bedtime habit, which was comforting for the kids.......and the only way they had been trained to know how to settled down to sleep, and it seemed easier for her as opposed to weaning.
Secondly, I would think the ones who were nursing would psychologically connect the loss of mother's nursing/milk with her leaving them and the home. So when she shows up to tuck them in bed, of course they want what they remember as being emotionally secure.
Her trying to get all of them to sleep in the same bed, while fighting off the one who wants to hold her breasts to go to sleep.......well, no wonder she was frazzled. Seems she would have learned on the first child. But that was her choice and now she is having to deal with the results.
Switching beds during the night or allowing kids to sleep with the parents is very difficult to overcome without the shedding of tears at some point. I know when a parent is exhausted, you will do most anything just to get some sleep, but you set yourself up for months, or years, of nightly negotiations and/or interruption of sleep.
Have you considered bunk beds for the kids? The oldest one, especially, needs to sleep without his siblings. All of them in the same bed is establishing another emotional situation that will be more difficult to break later.
It is not about what you feel should work in your M. It is about doing the work that gets the right results. Do what works!
