For a couple of heartbeats, Ginny considering letting Percy do exactly that. Telling Ron, letting their brother rage and scream and siphon the inevitable anger and hurt onto him. But she also knew she couldn't do it. Ron's emotions where Percy were concerned would be far too volatile, and he didn't have the benefit of knowing that Percy had come back or where the family stood with him now.
She wouldn't throw another brother to the wolves just because it made her life easier. That was cowardly. "No, I think I should do it," she replied, reaching out to grasp Percy's hand and give it a squeeze. "He's going to be angry and hurt, and I don't think it's fair that he take it out on you. But afterward, he may have questions I can't answer."