The stress this puts on them is brutal. At times they will look 5-10 years older. Reading into your post the guilt she probably has with the kids could be driving this. Its part of the crap sandwich MLC serves up.
The emotions you will experience are going to be all over the place in various degrees .... just know its normal, you have a right to be angry/sad/ all that and sometimes all at the same time, process through them and own them ... sometimes I had to just sit with my anger outside for 10-20-30 minutes in order to find center again ... you too in time will find peace despite all this.
