Ron nodded thanks to Hermione when she brought the tea, but he couldn't drink it. Normally he'd take it for something to do but he just didn't have the ability to make himself do that sort of thing right then. It was hard enough say what he needed to say to her, especially when he knew how she'd react. And he knew that his preface of, "Don't freak out, okay?" was not going to work but he said it anyway.
"I do know that it's related to the others, 'Mione, because I er, well I saw her die. I was supposed to meet Penny today to talk about her brother but she never showed up and the lady at the book shoppe said that wasn't normal for her so I got a bit worried and went to her flat and, well - the murderer was there still and Penny was dying." Ron stopped there because he knew that Hermione needed time to react to the news and he didn't know how bad it was going to be.