I saw what happened. It's not your fault. If think she imagined that you could do it like a roleplay scenario but honestly, It would be hard to control something like that with 10 people and I have been in crazy fast moving roleplays with just 5 people. You can run your game how you want. At the same time though... if she doesn't like how the game is run, I think she has the right to pull out, in which case her character could die. There was no reason for her to get so upset though. It's not your fault.

10 plus people*

Your welcome. Also, do you create senarios without the characters in them then use a sort of random name picker to chose which characters do what? If so, I think that's and extremelly fair way to run the game. Even if it's not, I think that you are trying to be a fair as possible without favoriting. I will always be here for anyone that needs support or just someone to rant to.