Let it go.  She is 52 years old and she is who she is.  Presumably she does not live with you.  Just tell her that she is free to think what she likes and not to contact you until she gets over herself.

Write her off. As you would any toxic POS person.  You are 75 and should have long ago come to clarity on what to do with toxic trash.

Enjoy your life.

That this supposed adult (she is only 3yrs younger than I am) is perpetrating this crap in her 50s highlights her unequivocal status as a POS. Do what you would do with any turd. Send it down the toilet bowl tornado to the sewer and out of your life never to return.

I'm sorry - you've clearly tried to do right by this SD but she is who she is, at this point, and not worth your time and effort. Write her off, hard as it may be.

She’s cruel to you. Block her from ever being able to see you again.

they have behaved like that their whole life, their capability for change is pretty much nada.

one of my 1st cousins is a horrible person, so bitter angry, meddles in other peoples marriages including her siblings and makes people fight. She thrives knowing how bitter people are around her and fighting.

i also believe in karma, when she was 50 plus with a then 10yr old son she got news her husband dies of a heart attack overseas. He was flown back and after burial she goes to try cash in on his life insurance policy. Insurer says wife already collected. Turns out her hubby married a 2nd woman and she got everything. She was such an angry bitter person that her own inlaws preferred the 2nd wife and wanted nothing to do with their son’s only child from her. She was left penniless..

she cried hysterically and you would think that would put things in perspective but no, she is causing issues just like before and is in her late 50s now..

she even badmouthed me to family over 2nd and 3rd hand info she got off people who knew jackshit about me and couldn’t care less she was spreading lies and seriously damaging someone’s reputation and image. I have no relationship with her

so truly let it go. At age 50+ she still wants to be a bitter hormonal biatch then so be it. Enjoy your life. Karma is waiting for her anyways. What you dish out you eventually get back

In reality it is SD that is jealous that her father has a new wife, this has nothing to do with her deceased mother.  The second you started defending yourself against her baseless accusations, you stepped into the ring so she could assault you some more.  

" I have found that people who swear on all that is precious to them...bad things happen to them"

This statement shows how immature and hateful she is. Please be careful around her.  

It sounds like she comes around often and you're not going to be able to completely avoid her, it would be wise to try though.  Getting busy with your own likes, hobbies, friends and family will be a great way to put space between the two of you. When she is in your company try to keep it brief and be polite.  I am sooooo polite to my oldest ss it's ridiculous, but am I friendly or let my guard down. nope, not for a second.  

Realize that your DH will never addess her behavior, if he's in his 70's or older he'll likely just bury his head in the sand and let things continue. Unfortunately as many of us SM's have learned, we're on our own when it comes to skid assaults.  Just because you've helped her out and you're an amazing strong person does not make you exempt from SD's wrath. She lost her mother and in her mind, her father too after he remarried, so she's going to be angry and there's nothing you can do about it unless you leave the relationship with DH.  If you're going to stay please learn how to disenage from her while allowing DH to fully enjoy his darling angel daughter.  

My god I'm at breaking point at 39 you have to listen to what people are saying and  enjoy your life, I can't imagine how you are able to deal with it, you don't survive cancer you beat it and live with its after math you don't need anything else bringing you down, I won't pretend to everything, I know my mom beat it 5 times before i lost her , get rid of the hassles you don't need x

you can do it.

Like Rags often states, "Toxic people get a total write off." I mean, think about it, why should you compromose your joy and happiness over her bitterness? Why does her satisfaction come at your expense? That's insane. I have been swept up in this mess for a long time, and my husband just let it all happen. SD could say and do anything to me without a single word addressing her behavior. I'm still contemplating filing a restraining order against her, as she will come back worse than ever. We have to teach others how to treat us. I have standards for how I expect to be treated, and SD has failed miserably, however, you must realize your DH is first and foremost your PROBLEM. As someone stated earlier, if he's 70+ he's been burying his head in the sand a long time, and the way he deals with things, (like my DH) is to not deal with them. His passivity has put us in a terrible place. 

Many recommend disengagement, which is different to many people. For me, I feel SD's transgressions have been so horrible, and DH has enabled them, that he deserves to be uncormfortable too. After all, nobody has been concerned about my comfort level, and my desires. If he cannot stand up to his feral princess, and defend me, himself and ultimately, our marriage, then, sorry, you've lost your privilege of visiting with her, and having her in this house, or otherwise in our (his) presence. I refuse to play that. When she can own her behavior, and make the necessary changes (narcissists never do this by the way) then we might have a discussion about how that will look and feel. This just isn't working for me, nor do I EVER SEE IT WORKING FOR ME. This triangulated dynamic is like dancing the emotional tarantella.(Google Nora/Tarantella to get the full value here).

The main take away here, is take care of yourself, because you truly are on your own. It's earth shattering when we must face the marriage we thought we had was nothing more than an optical illusion; a fantasy. In reality, these men mostly care about their comfort level, and that of their adult "kids." 

I wish I could be more optimistic, but I am a realist who is solution focused. There's no future in the past, and nice girls finish last, sadly. 

No reason to defend yourself against somebody like this, nothing you say will make any difference.

No reason for you to subject yourself to her presence, either.

Listen to all the above.  I dealt with one like that who was also, shall we say, crazy.  I tried, did counseling, separation from H etc. and she continued to butt into my life with her toxicity and caused trouble for me.  After a long time and what I thought would be new starts from H I finally told myselt - self, why the h*ll are you putting up with all this carp at your age.  The problem, also in her 50's is crazy and never going to change, and H keeps letting her into our lives to cause trouble.

I was, and is a long tough road.  right now we are separated by lots, and lots of miles.  I haven't talked to him in months and am quite content not to hve the strength and aggrevation.

I agree with all the other posters.  You have to remove yourself from this craziness you did not create nor are you responsible.  He is not going to protect your emotional health; so turn this into a positive. Thank him for handing you the gift of not dealing with his familal toxicity; it was like this before your time, anyway; it will always be this way.  He is their doormat and they will continue wiping their feet on him unconditionally. The hardest part, but the best part for us, given this sickening position...is accepting that fact.

You, on the otherhand, can find peace by cutting off the drama--completely, just do not play their games any longer.

I disengaged from SD20 a long time ago, and envision a time when she will regain contact with DH (for money or a place to live), however I see nothing from her current behavior that tells me I ever need to regain contact with her ever again, not in this lifetime or any lifetimes.

Narcississtic people dont change and SD20 Feral Forger will never change. She lies, she steals and its only gotten worse with time not better. I read your chilling post and those preceeding and thank my intuition that caused me to back off a while ago - Im so sorry that you rode this ride for so long! And your DH has no wherewithal to stand by your side, just allows it to happen.

I hope your wills are all in place! And you have a good life insurance policy for DH. Im working on that right now.