Is this typical of seniors with dementia?

People with dementia, depending on type and stage, may still have motive and be capable of manipulation, but they are not as skilled with it and try to pass off things that are patently absurd and conradictory and may also try to attain things that are either impossible or not in their interest given the situation.

But even more commonly, and maybe more to the point and the word you are looking for, it is confabulation. Things are not right. The brain tries to fill in the gaps and make sense of what is wrong. It is not lying as much as wishing, or not being able to tell the difference between a reasonable explanation and a random thought that makes no sense as an explanation but at least indicates the problem is not their fault or due to their problem with thinking...or even not being abel to tell the difference between a thing they dreamed and a thing that really happened.

Babalou is so right - make sure siblings realize that her statements might be innacurate. Sure, you have to consider the possibility that there could be some basis for complaints that could turn out to be real, but look into it first, don't assume it right off. So many people do not realize this about dementia, or are in denial about the dementia and somehow find it easier to believe that a loyal caregiver/loving family member has turned into an abuser or neglecter, or even a thief. It sounds like - and I sure hope- your brother already knows better and/or has checked his facts before reacting, so maybe you are all ahead of the game so to speak.

I don't think that this has anything to do with "getting attention". I think that it is much more akin to what happens when mentally ill people are questioned by the police. They'll admit to anything, they confabulate events, they collapse and expand time, they try to fill in the blanks for things they can't explain.

Don't ascribe motives to people with dementia. There aren't enough brain cells left for motive. Don't correct. Make sure that your siblings know to call you when there is a question about something they're being told.

And if it gets to the point where your care or veracity is being questioned by siblings or authorities, then it's time for that elder to be in care where there are lots of eyes on the situation. My opinion only.

Jeannegibbs is absolutely right. Mom used to be considerate to a fault, vain yes always, but she would always put family first. Now that her dementia is full blown she is not the same person. She's like a three year old who tells you whatever story seems to fit. One day she will refer to a fall she had a year ago as if it were yesterday. The next day if you mention her falling, she will claim it was a long time ago. She has bruises sometimes, but it is because her skin is thin and she is so old, sometimes the capillaries break on their own. The other thing is she will complain constantly about her constipation or diarrhea when she wants attention but when you bring up concern about one, she will say she has the other. She complains constantly to my sister and me, but says nothing to acquaintances, in fact denies it. Sadly, when a person gets that age, they feel powerless and the only way they have control is through getting attention. Yes, its brain damage, and its really really sad.

"I think she is just trying to get his attention."

No. Just NO. (Sorry, you've pushed one of my hot buttons.)

Dementia is the result of physical damage in the brain. Upon autopsy the doctors could tell you exactly what the damage is. (In my husband's case it was folded molecules of alpha synuclein protein.)

Dementia is not a psychological problem. It is not a personality defect. The damage in the brain may cause behaviors that look like lying, or attention-seeking, or manipulation. Sometimes these behaviors are unconscious and sometimes they are somewhat deliberate, but always behind them is the damage in the brain.

Keeping that firmly in mind is helpful in deciding how to deal with the behaviors.

When I call to my son or daughter to please bring me a glass of fruit juice, my blood sugar is low and I'm afraid I will faint, or I tell them dinner will be late because I has to deal with low blood sugar this afternoon, I am certainly glad that understand that diabetes is a physical disorder and I am not being manipulative or lazy.

People with damage in their brains cannot be judged or interpreted by the same standards they would be if they were "in their right minds."

She may have been remembering a previous fall and associated it with spots on her arms or something.

MIL has blue marks on her arms and legs that are not bruises, but she will poke at one sometimes and say that she doesn't know when she got it. She'll say maybe it was when she fell, yet she can't tell you when that was.

The word you are looking for is "showboating".

She is trying to get your brother to jump in his car and run to her side. Dementia is very sneaky and lies a lot. I would photograph the arms and legs and send that to brother's cell phone to make him feel better.
I hate to say it but pictures like that will protect you in case she tells a lie to someone who calls APS. It can happen.