L.K.
My daughter did the same thing she slept without waking for a feeding for a while, then all of a sudden she wanted to eat in the middle of the night. Like you I tried to not feed her thinking she was just in a habit but if I fed her she would go right back to sleep and sleep the rest of the night. If I didn't feed her we were up every two hours. She eventually worked it out and now she dosen't wake up for food anymore. Her pedi said she was probably going through a growth spurt and to feed her when she's hungry. She did tell me that I could try giving her formula for her nighttime feeding that the formula was thicker and might stay with her longer. I didn't want to start formula at that piont but it may work for you. GOod luck!!