Advice of how to have a difficult conversation

[Sandbox Sally]

I would say something like,

"Listen, I just want to clear the air here about what happened last week. I got the impression that you were unhappy with me, and I just want to give you the opportunity now to let me know of anything that's bothering you." Let her react in whatever way...

Then something like, (calmly) "ok...I have to be honest and tell you, I felt pretty disrespected when you yelled at me, and it made me very uncomfortable. I'd like to know that nothing like that will ever happen again."