Hi BBD, I'm sure you will get some great advice from many parents here!
One suggestion I'd have is for her not to fall asleep while breast feeding at night (perhaps you might need to make her second nap later in the day or get her to bed at night a little earlier) so that she goes to bed awake. I would guess she wakes up and wonders where the breast has gone as it's the last thing she was doing and it soothed her to sleep.
This might be so too, as you say she sometimes bf at night. Theoretically she could be getting enough milk/food during the day and doesn't need night-time food, but likes the comfort.
To nip it in the bud you might need to get some tips on stopping bf at night (unless she is unwell or wakes up stressed after a scary dream or such).
We had some rough times with our DD waking up at night and found that sticking to our guns and the plan we had set (which didn't involve rocking to sleep or milk etc). She learnt soon enough that we'll be there for her, but she also learnt how to put herself and resettle on her own, which is invaluable to her also. Tough work though

Some things we did were to sit by her cot and sing a song while rubbing her back. Then after some time, we would gradually reduce down the time we pat/shhd or sang a song. We would never revert back to rocking/feeding/cuddling, as you go backwards because they know they can get you to do it.
You may find too that she will get a better night's sleep when she wakes and settles herself independently (as well as YOU!!) and improve her sleep as a result.
Hope it gets better for you soon! char
