Hey /trv/. First time on this board. I'm sorry if this sounds like a silly question:

I'm going to be traveling to San Francisco at the end of this month. It will be my first time on a plane. I'm bringing along my girlfriend, who has low blood sugar. As a result she has to carry a lunch box with her to have things to snack on readily available. Will they let her carry the lunchbox on the plane? It's metal... if that helps.