"He's just worried about you," Barbara said shaking her head as Galen accused the Pokemon of being a traitor. "This is Lucario, he's a pokemon," She was surprised to be making introductions, but guessed that if she'd woken up as a child she'd have been weirded out by her own pokemon too. "He's a friend of yours, you two train together." She added, because she had a feeling friends were something that Galen didn't have a lot of at this point in his life.
She fixed him with an unimpressed look when he called her old, but didn't rise to the taunt, "I don't know your master." It felt safer to go with something like that than to remind Galen that his so called master had killed his family and then raised him only to betray him in the end. "But I am your friend, we met a few months ago, I was there when you found Lucario."
As for his food, "It's going to make you sick if you keep eating that and not any real food." She warned him, "I'm your friend too, like Lucario. I just want to make sure you're taking care of yourself."