The time she is actually asleep
Always wake her up for feedings as you have been...however, if she's had particularly rough naps, I might let her sleep an extra half hour over feeding time if she's actually sleeping well for one nap. But definately no more than that.
The three hour EASY includes 1 hour for feeding/playing (in your lo's case, feeding, diaper change then nap), and 2 hours for sleep (but if she wakes early, don't sweat it, play with her for a few minutes, then feed again, diaper change, then back to sleep).
*HUGS*
Sonya =P