TH is allergic to shellfish. When she boards the plane, she informs the FA and if the meal has shellfish, she is offered the alternative.

AS does not FEBO like AA, so its sort of hard to decide where to sit if your meal choice is that important to you.

I like the idea of a kebab, but my guess is that DCA does not afford such delicacies.

In fact, the DCA gates don't have much of anything. If you are on a F ticket, don't forget to visit the CO lounge -- it is lovely.