Skyblock Command /is kick [playername]

My name is BadAssHog1506.
I play Skyblock alot and I have a very good island. But my problem is that the friend I invitedis griefing on my island. It would have been so much easier for me if /is kick [playername] was fixed because she has griefed me many times. Please fix this command as quick as possible

Many thanks
From
BadAssHog1506

 

also try /is ban

 

But /is ban only bans them from warping to my island which means my friend can still access my island. She can only access my island because I invited her

 

The command to remove them from your island is /is remove >playername<

 

That still doesn't work it says no-one else is on my island when my griefing friend is.