"I used to know someone like that, he was caring and absolutely selfless I admired him a lot." She said wistfully, the past tense a clear indication that the completely non-existent person was now dead. Bellamy could draw his own conclusions, or rather the one Gemini hoped he'd come to, that Clarke's activities would lead to her death. A person would do anything when they thought the ones they cared about were in danger, it made them desperate, irrational, things that would be needed to wrench Bellamy down a darker path.
"I've think I've been talking with the same people," she lowered her voice even further, looking even more nervous. "I don't know who to trust either," she admitted, sounding anguished, "but they do seem to be able to protect us, offer us a better life, rather than just grim struggle without any hope."
Her words were carefully calibrated based on what Bellamy had said about his own world, tuned to match his thinking and direct it in a positive (for her) direction. All of it was delivered in a worried, vulnerable tone that would hopefully have him wanting to protect her too.