Do elders with cognitive decline/vascular dementia who have no assets (only has a pension and SS) need to have a will?

One can only create a will if one is in their "right mind" and can comprehend what one is doing. If this describes your mom and she chooses to do this you can go to Legalzoom.com and they will create a Last Will template for her state of residence that can be customized with her intentions, downloaded and legal (if completed per their instructions). Last time I checked it was less than $200 to get this. Print it and she can sign it per their instructions-- IF she doesn't have a medical diagnosis of incapacity, cognitive impairment, etc. If she has some mild short-term memory issues but can understand what she is signing and what it means for her at the time, then I think it is ok for her to create it. My will also contains specifics regarding my funeral, so this desire can also be captured in this document.

I think you need a lawyer. But I will put my 2 cents anyway.

I am assuming the son you are talking about is Moms brother. It all depends how ur Moms parent's Will was written. If the property was left to their son outright, your Mom has no claim. Brother can leave it to whom he wants to. If the Will was written that the property was left to the son for his lifetime and at his death it reverts back to the other children, then eventually Mom will get her share. There is also a "trickle" down effect. This happens when a Will is drawn up and the beneficiaries are the children. If a child dies, then their children inherit what their parent would have gotten.

I think the first thing you need to find out is how the Will where brother/son inherited the property was written. If the property was probated, a copy of the Will should be filed with the County Clerk. Once you find that out, then you can proceed with getting a Will for Mom drawn up.

I have a neighbor who worked in the Probate office in our County. She explained to me how Probate works in my State.

Executor, this person is assigned in a Will.

Administrator, person applies when there is no Will

Affidavit, When an estate is under a certain amount of money, in my State its 20,000. No need for Probate.

All of the above will give you a "short certificate" to give you authorization to pay bills, close accts, speak with people, ect.

IMO, you can't drawl up a Will on something you "may" inherit. Grandparent's Will could say that upon Sons death property reverts back to living children. If Mom passes before brother, than she would get nothing anyway. There also could be a clause that those inheriting cannot sell the property. This means that Mom would inherit the upkeep and taxes. You really can't make any decisions until you see that Will.

If you can obtain a copy of that Will, please come back and tell us how it all works out. We learn from others.

I disagree with Burntcaregiver that a will is needed. There is no estate, and a probate often isn't opened in the case of small estates. Any bills that come, say for a phone or whatever she has at her facility it is returned "Deceased: No Estate." You are not responsible. Her inheritance doesn't pass to anyone then unless this home that may or may not be settled says "If any heir of this will is deceased then the division proportion due them shall pass to their children", then her "inheritance that may or may not happened remains there." If it happens she loses her medicaid and she will have to pay for care until she spends it down; if a large amount that is the time for the will.
You should look up this question for your own state. Otherwise, if your Mom dies you can be the "good person" who notifies anyone she owes money to.
Do know that if there is a spend down account she has in her name, this won't pass to you unless there is a POD to it. As she will have died without a will it won't really go anywhere.
A simple will is inexpensive. For myself I think I might do it, but if you are executor then you do have to do the whole thing of getting EIN, filing taxes and all that for no real reason.
Why not ask a lawyer in your area. Here you can see that a forum can give you varying advice and opinion. It is best with all legal things to stay safe rather than sorry.

I'm surprised that when she did her DPOA the lawyer didn't also do a will with it.
Yes, your mother most definitely has to have a will made even if she has nothing to leave. When a person passes away DPOA expires too and then whoever is the executor of the will is in charge.
If she has a checking account, you will no longer have access to those funds or be able to close it. If she has credit cards you will not be authorized to shut those off either. Or even household utilities like electricity and cable. Someone will end up having to be appointed by the probate court to even do these small things.
Take mom to the same lawyer who did the DPOA and have a will made up immediately. Otherwise it will be a very rough road and an expensive one when she passes away.

She can't leave nothing to anybody, so I doubt she needs a will. If she inherited money from the property, then yes, she would, but as she doesn't have that now, she can't exactly put it in a will.

If she has any low-ticket personal property she'd like to leave to anyone, she could write that down in what's called a holographic will. It's the least "legal" will out there, but if her things aren't worth anything beyond sentimental value, it's plenty. It just tells folks what her wishes are.

For example, my spiteful grandmother had nothing, but she wanted to make good and sure she disinherited one of her sons. She wrote a holographic will to leave him one dollar, and to split the rest of her estate between her other two sons.

My dad, bless his heart, went to the trouble of finding ten dimes from the year his brother was born to send to him, and the dollar came out of his own pocket. The disinherited brother got more than anyone else. Go figure.

And no, my dad never officially filed the will for probate.

It can't hurt to make a will, leaving her estate (whatever it might be, even if it's only her button collection and comfy slippers) to her heirs.

In any case, she can't have *no* ideas about what she'd like to happen to her belongings, and what arrangements she might like in preparation for her passing. This is a good opportunity to take down her instructions.

I don't know, of course, but it sounds to me from what you say as though your mother actually has title to that 1/3 of her parents' property right now; but your uncle has the right to occupy the property for as long as he likes, and on its sale your mother and the other sibling (presumably) must then receive their legacy share. The open question would be whether your uncle's heirs can continue to occupy the property. If you're on good terms with your uncle, it might be sensible to clarify exactly what the position is - you can explain that you're not rubbing your hands over the inheritance or anything vulgar like that, just dotting i's and crossing t's on your mother's paperwork.