That was my take; normal legacy airlines (that would be big-name international carriers in virtually every country other than the USA and Canada) serve free food no matter how short the flight. She probably figured the FA left it for her since she was asleep. On a short flight, the free food will usually be a sandwich of some sort that they can hand out without a tray. It is this way on LH/BA/KA/CX/CA/many others.