Thanks for all of the replies. I think we are going to go into DCA first, just to get the pictures taken, because I have heard the lines aren't as long there. Even leaving here (No. Cal) at 4:30 in the morning, we won't get checked into the hotel/drop our bags off to be held and over to DL until at least 11:30 (more likely 12:30 or later). I know the AP line can be sooo long in DL.
Just to double check, my understanding is that if we go into DCA first, we can have the pictures taken there at Guest Services as long as we have it done before we leave that park that day. Is that correct? I think we will get it out of the way first thing anyway, so we don't have to do it with cranky kids later in the day.