Okay, I understand now. You’d be better off putting it this way in the first place, because “divorce” means the dissolution of a marriage. It has nothing to do with whom you might contact with and whom you “consider” your relatives.
Most states have some sort of provision permitting a court to issue a protective order of some sort. First, though, it’s likely that you’re going to have to have any such order enforced by the court where your sister lives, which means you are going to have to travel to that state and hire a lawyer there. Second, as a practical matter, it’s really hard to enforce such orders no matter what court you go to.
You should be able to get an initial consultation with a good lawyer without paying.
Let me add, unless you can show that there is some actual harm going on, such as a serious threat of violence to a person or a documentable financial harm to your business, you’re probably going to have a very hard time.
A simpler solution (if you haven’t already tried it) is to call the phone company and see if they’ll block all incoming calls from a specific phone number. My local phone company (SBC, Chicago area) has such a service; it costs $5/month (for businesses) and allows you to block up to 10 numbers.
You might want to check first, though, that it’ll work for out-of-state phone numbers.
When you say your sister is making the receptionist uncomfortable, is she threatening him/her? Because if that’s the case, you might have a cause for action.
More generally, you might want to look into harassment laws. They’re going to vary by jurisdiction, and you’re going to have to look at the laws in your state and hers, but assuming you’ve told her to stop calling you, it probably is harassment.
Just a hint…document everything. Write down the time and date of every time she tries to call you. Also, keep in mind that I’m not a lawyer and this isn’t legal advice.
I had a legal problem with an Aunt who lived in N.C. If she had taken my calls, the legal problem would have gone away, but she decided to be a stone head. It seems that the phone company can block her incoming calls unless you, the dialer, add a four digit number after the regular number. When I attempted to call her, there was always a beep after I completed the number. If the four digit code wasn’t dialed, the line went dead. This came out in court when I went down there. Very sneeky.
…and, oh, it ended up costing her mucho bucks because she blocked me out.