It took a lot of effort to act cool and unbothered in front of everyone.
Especially to Jake who was mockingly looking at her at the moment.
Of all the people who have found her, why does it have to be him?
She hated him. Aside from being her rival, he had something unforgivable towards her which made her to hate him more.
It was not unknown that each group or unions would put a spy in their enemies so they would know their every movement and to check what the enemies were planning against them.
And that spies would do everything just to extract essential information from them and then would give those information to their true groups or union.
Remember that girl whom she had considered her friend, she was the mole or spy who was sent by Jake's group to keep on tabs with them.
As soon as she found out who she was, she didn't confront her about her identity.