My mom has been saying someone was vandalizing her car and house. It is getting worse she has called the police 3X to come over to look at rocks missing and cracks in her driveway. You can't convenience her no one is doing anything.
The hard part is over.
I'm matching you with one of our specialists who will be calling you in the next few minutes.
I would start with your mom's primary care Dr. but don't be surprised if your mom puts on her "nice and normal" face for the Dr. The only person who really saw my dad's paranoia was me. If asked by a Dr. or other healthcare professional how he was doing he'd reply, "Oh, I'm doing fine!!!"
Her Dr. can evaluate her and maybe put her on some medication.
Is this recent behavior?