The type of person that acts entitled and looks to threaten others the way you have shared are themselves chronically unhappy individuals that tend to seek things outside of themselves to fill the chronic void they developed possibly from their early childhood.

This type of individual tends to develop alcohol/addiction problems to avoid feeling and they tend to lack genuine attachment skills. Sadly the spouse and family/children end up walking on egg shells and no genuine connection takes place.

There was nothing you or your children could do to fix this. Instead you have been fed the unhappiness is your fault when that is simply not true. Don’t fall into the mental trap of thinking someone else will get a true healthy positive. That is not something these unhealthy individuals can give or maintain. Actually, this will get even worse as she ages.