My dd would never wake for the df either (also was bf at that point). However, I wanted to give her that feed, so I woke her. Being a very sleepy baby, it took about 30 mins for me to get her awake enough to feed her, and then she was a slow eater. I didn't have to do a diaper change at that point, I don't think, but if your lo needs it you should change her. Anyway, I really liked doing the df b/c I stopped night feeds with dd at 8 weeks (she never woke for this either, had to wake her) and I was glad to know she had that extra feeding to hold her over through the night.