I feel sorry for your MIL because odds are that her parents were the same way with her.
Her parents D b/c I understand her father was an alcoholic. Interestingly her two elder sisters stayed with him and MIL and her younger sister stayed with their mum. they subsequently got a half brother from the new marriage. Two of her 3 sisters D their first Hs and two of the daughters of one of these sisters also did the same. BIL has also been M twice.
On the other side of Hs family his grandmother died of cancer (as did his father) and his grandfather remarried. When this lady also subsequently died he got another partner (fairly quickly). His only aunt on this side of the family has been M twice. His grandfather also suffered cancer but thankfully survived that despite being very elderly at the time.
His parents were M for 30 years before his father died. H was only 24 at the time and it hit him very badly. His personality changed over night. MIL remarried within 18 months which also hit him very hard.
Yes you do see a picture forming. Two in fact. A picture of D and a picture of cancer. Yes my H is damaged (probably beyond repair but I hope not) BUT unfortunately he has to recognise that for himself. The very sad thing is that up until Hs MLC took hold we had weathered all of these things together (obviously some occurred before we were born). I quite literally held him up when his father died and yet it is me who is now his cancer that has to be cut out.
Me 43 XH 45 M 2.7.88 Divorce 7.10.09 Kids D20,S17 & D15