I wouldn’t worry about it. The people she is writing to and calling can choose to not answer the call, put their phones on nighttime “do not disturb”, or block her number, then call her themselves at their convenience to chat. They can delete the e-mails without reading them.
The people who know her know that she is in assistive living, I’m sure the recipients have figured out there are cognitive issues too. Most people will be kind and ignore any inappropriateness. Those who don’t can be politely cued in. Those who won’t leave it alone can be ignored.
The facility will handle any really inappropriate calls (like 911).