[Balthazar doesn't seem like some all knowing being to her. He's a somewhat cheeky guy who seems somewhat hedonistic, if anything. She wouldn't think anything of it to ask him about what might or might not be toxic, just like she wouldn't hesitate to ask a native to any new area that she might visit what indigenous things to stay away from. It seemed logical to her to ask Balthy since he was older than dirt and would probably know better. And it would certainly be easier than trial and error, especially if there were errors.]

I can keep you out of it if you want, but I don't see why I shouldn't ask him if he knows. It's not like I'm asking him to magic us up some cheesecake.