Answer:
The first clue about the level of trust Jen had for Luke was when she bit her lip after asking if Luke could help with the rally. She bit her lip because she had not intended to disclose it to him yet. At least not until she was certain he could be trusted.
The second clue was when she asked Luke directly if she could trust him.
When you trust someone, you don't question the trust.
The third clue she gave was when she leaned her head back and stared at the ceiling after asking Luke whether or not he was an infiltrator and whether she could trust him.
In doing so, she was calculating her odds. She eventually held back the information she was going to share in the guise that she was not the only one involved.
It someone felt I couldn't be trusted, it may hurt and it may not. It all depends on how much I have done to demonstrate that I am trustworthy. In any case, trust is not demanded, it must be earned.
Cheers!