I'm not blaming her for anything. No, it isn't her fault that Ned died. I never said that. I made no argument about whose fault it was. However, it is a fact that she went to Cersei with Ned's plans. Disobeying her father because she wanted to stay in King's Landing living her fairy tale life. I believe this is after Ned is attacked by Jaimie and had his leg broken, yes? She ignores how things are because of how she wants them to be.
She was groomed to be a Lady of a great house? Does that not mean listening to your father? Does that not mean paying attention to the character of those around you? Joffrey was going to kill the butcher's boy and she lied for him. She's constantly doing stupid things because she doesn't accept reality. She wants her fairy tale. It's her character flaw, it's extremely annoying, and as of the recent chapter in TWoW Martin posted, extremely difficult for me to continue reading.