You can't avenge him from the grave
I killed your High Sparrow and all his little sparrows. All his septons, all his septas, all his filthy soldiers, because it felt good to watch them burn
Calling yourself queen doesn't make you one. And if Renly wasn't a king, I wasn't a queen
Cersei understands the consequences of her absence and she is absent anyway, which means she does not intend to suffer those consequences