This is tricky -- a few possibilities come to mind --
She could actually be hungry at the EW -- if you give her a quick bottle and leave, will she go back to sleep or does she still fuss for you? I used to do smaller feedings at the EW time and they eventually phased out on their own. But, if she's still not going back to sleep after the bottle, then it's probably not hunger.
Anything environmental going on at that point? Noises, heating/cooling cycles, things like that?
What about teeth? EWs and teeth went hand in hand for 2 out of my 3 -- in fact, it was pretty much the only time they bothered my ds, I never would have known he was teething otherwise.
It could also be that she's just adjusting to the new routine and this is the last part of it ironing out. Is she falling asleep easily for the first nap? With that first nap length, she could almost use another (small) bump in A time.