You can use something like this.

https://www.alzstore.com/teleCalm-phone-scam-repetitive-call-blocker-p/m005.htm

I would not get her a phone. As her disease progresses she may start making phone calls too often & at off hours. My father started calling up to 20 times a day often from 1am-7am. Taking the phone away was difficult and of course he never forgot or forgave us.

The phone would also be easily lost.

It looks like there are a number of options. With this one you can pay for a service to answer the 911 calls knowing about the memory issues. In any case on many phones you can likit incoming calls to those on the phone’s contacts which could help with blocking scammers.

https://www.razmobility.com/assistive-technology-blog/3-best-phones-for-people-with-dementia-or-alzheimers/

was intrigued by reference on another post about a phone that can only dial or recieve calls from 10 preprogrammed numbers. could someone advise brand, model, etc?

my mother has mid stage Alzheimer's, is now in memory care and on day 1 called the cops, thinkgin her stuff had been stolen [this was standard practice at her previous independent living place and did not endear her to staff]. now to reach her we call front desk and hope to get transferred through to her...think it minimizes the number of calls she receives. in addition she'd like to be able to call out. i'm worried about scammers and repeat calls to polie, but this seems like it might be a good way to maintain some social connectivity for her.