Marleysmom what is your DS doing when she wakes, does she cry, fuss or just want to play? I had a similar situation to yours a quite a few weeks back, he was waking between 4 & 5am crying, or at least I thought it was crying until I really listened and he was only fussing, I let to him to fuss and he fell asleep again within 5 minutes.
DS used to goes to bed at 8pm, then when he was younger wake at 2am then 5am, he then dropped the 2am when I changed to 4hr EASY and then he started waking between 4 & 5am, he did this for a while then he started playing with his feed, this is when I realised his cries where different.
If she is crying and not just fussing you could try PU/PD or Shush pat, an other option is if you know when she will wake set your alarm and go in before she wakes and place a hand on her.
Although it could just simply be that she is thirsty and she doesn't mind getting milk or water
