My daughter has this one friend that every time she comes over it is very stressful for me. My three end up fighting with her and it is always a big ruckus. Does anyone have any suggestions?
Why do they end up fighting? Is it something the girl does? It's hard to suggest anything without knowing a little bit about what's happening to cause it.
Figure out what causes the issue before you can attempt to fix it. It could be something as simple as personalities that conflict or it could be something worse.