Lucy does note that Gabe is being truthful about potential murder there, but doesn't comment on it. Archangel and all, goodness knows what they get up to. She doesn't feel like asking.

Instead she just sighs again. She's actually not that upset Peter got rid of his power if he was never going to learn to control it well enough for it not to be dangerous, but still. She's annoyed he hasn't told her, and that he made such a big decision apparently without consideration or asking advice. And to someone who apparently tricked him into doing it. Just. Oh, Peter...