How do I tell if my friend is showing signs of dementia--or just clueless and stubborn?

I have a friend who just turned 68. She is a widow with 3 grandchildren she's raising alone, w/o any parental help. Her DIL lost custody of them and her son is not in the picture at all--he has joint guardianship with her, but does not provide any financial aid at all. Lives in another state and will not come here to even see the kids once or twice a year. The kids are 11,9 and 5. 2 older kids are boys, the 5 yo is a girl.

I have stepped up the friendship level b/c she is burning out, fast. She lost her home to bankruptcy and is selling it this month, and planning to move to AZ with the kids. We live in UT. She knows ONE person in AZ. One.

The kids have been through living all around the country as their father is along distance trucker. The mother is a meth addict and in and out of jail. Both parents abandoned the kids and are perfectly happy to let Grandma raise them alone.

My friend, I'll call her Louise....HAS to sell her home. No hope there, of keeping it. She makes $1400 a month in pension. Her husband left her basically desitiute, a small savings which she has had to use to pay for the kids' needs. She will stand to make about $180K on her home sale, but she needs every cent to bolster her income. Her son is in ND trucking for an oil company. She tries to get in touch with him and beg him for support for the kids and he rarely even answers her texts. He will not allow her to call him. She was texting him daily for 2 weeks and ONLY when she said she'd listed the house, he suddenly responded that he'd move to AZ with her and the kids. He keeps on asking "how much are you going to make on the house?" (Are we seeing a pattern here???!!!) She's so ecstatic he even answered her texts she can't see that he is planning to clean her out.

She has a HUGE support group with our church and neighborhood. Those boys have 40 fathers!! They are looked after and protected and taught. Their "bio dad" is an alcoholic loser who showed up for all of 6 hours back in April, got mad at the oldest son and took off. Hasn't been seen since.

I am watching my friend slowly deteriorate into a person who cannot make a decision, who has nonstop physical tremors, screams loudly at the kids whenever they disobey--- she hasn't always been this way. I do not understand the need she has to uproot the kids, when they are FINALLY stable and doing well.

I have put the cost of storage pods and moving costs on my credit card--b/c while I DO NOT support her crazy idea to move, she would be literally thrown out in the streets Nov. 5th. She is also a hoarder, and so cleaning this 4,000 sf home when she won't let anything go has been intensely stressful.

My concern is really that she is starting to show signs of dementia. I am NOT familiar with what that looks like! She has become incredibly forgetful, angry and unable to make the smallest decision. Understanding that she is under amazing stress, I can accept that part of this may be that stress---but she can't funtion w/o me or someone else basically "bossing her" to move. I go to her house to help and she is either asleep on the couch or sitting in a recliner looking at FB. Until I show up each day, she sits, frozen and unable to think.

Her son is a waste of space. She lives for him (only child) and will never do anything that may remotely upset him. The pods are about 1/2 full of garbage he's dumped at her house over the years and she will not toss a single thing. And he's a hoarder too.

She's thrown 2 blot clots since she gained custody of the kids..Neighbors and church stepped in and took the kids for 2-6 week stints. Son never came home nor even answered calls or texts to him to PLEASE come home and care for his children.

My real question: what does the onset of dementia look like? Am I looking at it with my friend? Her personality has changed, she is so angry it's scary. I understand that she is under untenable stress--but this behavior, the indecisiveness and amazing anger are new. Also the forgetfulness. I go 4-5 days a week to help her and have for the last 3 weeks. She yelled at me several times on Friday for no reason and I simply told her I was going to continue pushing her and to please quit yelling at the ONE person who is "there".

I am worried sick about her. If she'd stay in the general area, we could all keep an eye on her and the kids will be safe. She moves 800 miles away and her son is in the picture, something happens to her--he'll take her money and pop the kids into foster care. He's done it twice before when they got on his nerves.

If it was her alone, I'd worry, but she has these troubled kids---they're who I really worry about.

Help! Am I seeing super-stress or someone who is slicing into dementia? (Her mother and aunt both had it, bad, and young.)

Any ideas? I'm at a loss here.