It's been a week since I found out about the tournament, I might have known about it before, but in my mind, it was just background, unimportant information.
That day I spent hours talking to my sister, I made my anger very clear that she knew something so important without telling me when lives were at stake.
I understand her thinking that knowing or not knowing this before would have been irrelevant, this city is too big and has too many people, and finding traces of an Evil God here was very difficult.
But deciding not to tell me prevented me from even thinking about alternative solutions and having to investigate from scratch, so I threatened her not to let her enter the Dungeon again, it was an empty threat and she knows it.
My goal with all this drama was a warning to her, I don't care about her thoughts and personality, but I need to trust that she will act and talk to me about matters of this level of importance.