Frustrated, I’m so glad that you managed to have your estate concerns resolved and no longer have that worry hanging over your head! People like your neglectful SD are dangerous in their greed and determination to exploit elderly parents and even neighbours! 

It infuriates me to read about vulnerable seniors being scammed and robbed by whom I consider to be, ‘the lowest of the low’. In these days of internet thieves who prey on susceptible and often too trusting elders, it’s all too easy for the unwary to be cheated out of monies that they can ill afford. Oldsters need their children and younger relatives to advocate for them, rather than skulking around, like vultures, lusting for an inheritance. Your SD disgusts me.

My MIL is the eldest of three girls.  Her youngest sister was Dx'd with a fairly rare terminal cancer.  That aunt had a completely bizzare adult life. She married her University BF, aborted multiple pregnancies, they had three children, he was kicked out of the USAF for conduct unbecoming. He was a fighter pilot.  He then went to work for a railroad as a locomotive engineer. He did that for a couple of decades.  He had the same run his whole career. On the far end he had a secret marriage and family.  When the aunt found out he was a bigamist she divorced him. They never told anyone including their kids they were divorced until all of their kids were out of HS. He would stay in their family home when he was on that end of his run and they pretended they were their usual happy family.  After the youngest finished HS, "Surprise kids, we have been divorced for 10 years".  Their kids were then introduced to his other wife, their Step Sibs, and their younger half sibs by their adulterous bigamist fornicating locomotive engineer father.

The aunt ended up having to sell the house before forclosure. Once their youngest graduated daddy cut the aunt off.  She ended up with a long-ish term BF for the last decade of so of her life. They met at the Chemo clinic while he was taking his last wife for treatment. Come to find out, he had married and buried three terminal cancer patient women before he hooked up with DW's terminal cancer patient aunt.  She would not marry him but she did burn all of her assets while she was with him.

He was significantly older than the aunt so it did not fit elder abuse but he was a dirtbag of monumental stature.  All of these women were either widowed or divorced and he preyed on their loneliness as they went through their end of life cancer journey.  

When the aunt died they had burned through all of her resources.  He kept her ashes and still dangles them in front of her kids to try to get them to engage with him and give him money.  

When we would visit I caught him a number of times peering into our car windows. He was always disappointed when he figured out they were rentals. Until the last time. We road tripped to SpermLand to visit my ILs in one of our vehicles. That was the trip when we went to collect SS from his last SpermClan visitation just after his 18th B-day.  That weaselly old fucker keyed on our car, on DW's clothes, jewelry, shoes, purses, etc...  Asking how much our car cost, and the cost of anything else he keyed on. I had to take him for a behind the bushes talk to give him the clear message that nothing about us, our lives, or our belongings was any of his business.  He avoided me for the rest of that last visit and left to his hole in the woods leaving the aunt with the family until we left. He then scooted back to get her away from the family.

No one in my IL clan gives him the time of day but it would not surprise me if he has burried a couple of more terminal cancer patient ladies. His MO is to take these ladies on adventures in his RV to isolate them from family.  They live in his RV on some land that he owns on the edge of a Nat'l Forest. Though he does get them to their treatments and Doc appts.  They stay with his victims families when in town for medical care.  Fortunately my IL clan and the aunts kids did not let him in their homes.  That irritated the aunt but.... the general perspective on that was tuff shit.

Feeding people like this including the entitled gimme, gimme, gimme focused Skidult death watch vultures to the pigs on the local swine farm at feeding time is just IMHO.  The earlier the better.

As Rags's post indicates, these types are, sadly, everywhere. One of my sisters, the one who tried to be mini-wife to our father, is a charmer. She'd meet older people who had antiques she liked and would "borrow" pieces of furniture from them. The older people would die and the antiques would remain in Mini-wife Sis's home. Mini-wife Sis always had a sad story to tell older people to gain their sympathy. She'd come home from our oldest (widowed) aunt's house with "care packages"--boxes of food and other goods.That aunt, along with our mother, each gave Mini-wife Sis $800 several years ago for a mattress for her supposed aching back. The thing is the bed cost $800, not $1600. Finally, our cousins told Mini-wife Sis to get lost. (How embarrassing)
Mini-wife Sis turned on the rest of us siblings after our father died because she didn't feel she got enough money from his estate. She hated our mother and had very little to do with her until our mother became terminally ill.  Our mother once asked Mini-wife Sis what her plans were for retirement. Mini-wife Sis replied, "My inheritance from you."
Again, after our mother died, Mini-wife Sis threw a fit because she didn't get more than the rest of us. She has badmouthed us to anyone who has ears (ridiculous). We haven't spoken in nearly a decade. But I did hear from another cousin that Mini-wife Sis scrambled down there after our uncle died and she had the audacity to ask our cousin if she was in our uncle's will!
It's so relieving to wipe these people out of our lives. They are vultures. Greedy, self-absorbed vultures with no moral compass. And they LOVE older people, especially older people who are alone, who have money, and who are desperate for company. Another word for them is evil. 
You KNOW what SD is about. You know the name for her. 

SD wants to control your life.  I hope you have it worked out  if you died first  that your money goes where you want it to go.  Giving it to DH to mangerment the money. Means SD will get her hands on it. 

DH’s ex Meth Mouth is one of these people.  She works doing in home health services for elderly, but she pretty much does it to steal from them and take any drugs that are worth her while or worth selling.  The worst part of it she puts it our there like she’s this concerned victim who just wants to care for the elderly and people believe her bullshit.  I remember recently she was taking stray injured animals and trying to “nurse” them back to health all on her own then crying and whining to the world at large when these animals died.