Juliet Was Wrong
Daisy was furious at Juliet's accusations toward Leo but it was impossible not to wonder if there was some degree of truth to them. She knew he was a fire mage and that was his most closely guarded secret. He wouldn't have told her about that.
She also knew about his alias, his eyepatch, Daisy saving his life, and that he wasn't from Mirea. She definitely had some sort of otherworldly information since he was such a private person that he wouldn't even tell certain things to his wife…which made a lot more sense if he truly was out for revenge.
Leo wasn't very forthcoming about his past. She knew his family was dead and that he had loved them very much but he never told her how or when it happened. Or why he showed up at her farm on the brink of death, bloody and suspicious of her motives for helping him.