She's getting very agitated and irrational, and I think it's time to talk to the doctor about medication that addresses her behavioral issues. Problem is, I don't really know what to consider potential psychosis and what's just natural progression of the dementia.
Yes, I think your instinct is the right one to get her evaluated by a doctor, preferably a neurologist who has experience with dimentia. Often times patients with dimentia are perscribed antipsychotics to lessen the bouts of irrational behavior, particularly if someone is becoming violent.
BTW, did your mother sign a Durable Power of Attorney for Healthcare?
The customer isn't a moron, she is your wife -David Ogilvy