A number of things you said about the late BM, applied to the one in my life, NPD BM, who is still very much alive and kicking, being 12 yrs younger than me. Like yours, my DH went over and above what he really needed to pay her in CS, and of course as such she was always trying to wring the last little bit of £ out of him.   Also like yours, NPD BM has a histrionic personality and is a very high conflict, dramatic person.  She and her daughters seem to thrive on constant arguments and shouting matches, then five minutes later they're getting tattoos of each other on themselves, which I find bizarre.  NPD BM has not mellowed into a good anything.  She is in an abusive marriage but will not let the Walking Wallet go, for obvious reasons.   

Unlike yours, NPD BM does not have a lot of friends due to her awful personality, and is not pretty - she looks like a witch with a long bony nose.   I have never had an ounce of jealousy of her - but I would never say a good word about NPD BM.   I wouldn't pee on her if she was on fire - she ruined my life for over a decade.  She is vile and I hate the very bones of her. 

DH & I are together almost 34 years.  My biggest regret is all the free headspace I gave BM for too many years.  Like u I compared myself to her.  She was what I would call a girly girl, hair always done, make up always on, prone to frilly bedazzled clothing. She was also a person who loved drama, so much so she would create it if she felt that she wasn't getting enough attention.  I am neither of those things and I had to understand that DH chose me because I was intellectually curious, loved the outdoors, hated drama and on the whole a glass half full kind of person.
 

The best things that happened our marriage were a move out of state and me making a decision to remove BM from our day-to-day.  If it was happening in my house or to my family BM had no need to know.  I worked hard to disengage from decision making related to the kids. OSS at 16 destroys the brand new car he had to have and was arrested for road rage?  Gee sorry to hear that, moving on.  SD pregnant at 16?  Boy that's tough.  It was hard, damn hard.  But overtime, and for the most part, DH and I have had a marriage focused on us w/o a third party.

BM is dead now and one of the things I refuse to do is engage in the effort to canonize BM.  If someone, anyone, tries to paint her as a lovely caring wife and mother I factually correct them.  She was hateful and petty and tried to nickel dime DH for years.  She painted him as a deadbeat to the skids & his family and succeed in alienating his daughter. U don't get to be awful in life and then a saint simply by dying.  She never apologized to DH let alone me.

I count down the days til the SKs are old enough that BM will be a distant memory like a prison sentence.  Luckily CS is not an issue, but she sure enjoys PASing in order to cause disruption to our lives. I make no effort to have anything to do with the woman. I hope one day SO will just accept the harse reality that one day she is not going to magically wake up and actually care more about her childrens best interest than satisfying her own need to be bitter and angry. Her disdain for SO and I is simply because her life sucks and and she refuses to accept the reality that it is no ones fault but her own. She got everything when they broke up he left with nothing,  she still blames him for losing the house, cars and so on,  because in her mind he should have still been supporting her simply because she bred his children. Not her or her mooch of a brother who moved in with her felt it was thier responsibility to pay the bills. Also the fact that in the last 12 years her sole focus was to find a man to support her and her brood of children, has not yielded positive results.

To make sure BM disappears from our lives forever as soon as the kids are old enough I am moving as far away as possible.