Toxic sister turns possible crasher

Hey guys!
I’m working on my guest list and have stumbled into an issue that I can’t solve without feedback. My half sister is Practically disowned by only me. I have tried to reason with her and she doesn’t ever stop trying to sabotage any family events that she is specifically not invited to but hears about it from my grandma. She listens in on phone calls and lives there so I know for a fact she will know all the information for my wedding.
No one is willing to stand up to her even though they agree, the way she treats me is ridiculous but they won’t do anything about it because my grandma has made it very clear that she expects my sister to be invited. I haven’t sat down with my grandma yet but, I’m pretty sure she won’t respect that I don’t want my toxic sister on a day that is supposed to be relaxing for me. Not inviting my grandma all together isn’t an option. So... should I hire a security officer to attend the event in case something does happen? Or maybe just have one of my friends stand at the door to turn her away. It sucks really bad that I have to worry about this stuff but I want one day where I can not have her there since we’re paying for it. My grandparents also would stay if my sister was turned away but they will make sure she knows when it is and where. I don’t know what my best move here without jeopardizing my relationship with my grandparents that she’s depending on.