Has your dd always been a night waker? Are you co-sleeping? I am and my ds nurses frequently throughout the night, still. He has always been a night waker. Lately, tho, he has been cutting molars so his night waking increased. It is natural for an infant in the first year or two of life to wake frequently to nurse, but that does not mean wake totally up - just enough to latch on and fall back to sleep again (you should be able to sleep, too, while nursing, and you don't even have to wake up all of the way). The breastmilk is most nutritious at night with the highest content in fat, which makes sense bc as a baby grows and becomes more active, he might nurse less during the day and make up for it at night, when he is actually growing the most. A baby's sleep cycles are much shorter than an adults, which accounts for a baby waking every hour or two; an adult prob wakes every three or so hours, but doesn't realize it (unless you get up and go to the bathroom). If a baby is cosleeping and accustomed to nursing throughout the night, then he/she is more likely to want to nurse than a baby who does not cosleep and soothes himself back to sleep.
Other reasons for night waking: developmental milestones, such as learning how to crawl, walk, talk, etc. can disturb a baby's sleep. Teething, of course (especially molars; my ds has been affected for months by his molars coming in). Allergies are very tricky, but it has been proven that milk and or wheat can cause only night waking. You have to completely eliminate one or the other - not even a teaspoonful of milk in your coffee - bc the milk proteins hang around in your system for weeks. Milk proteins are very hard for humans to digest (especially babies) and are not even meant for humans to consume. Human milk is for humans. Goat or sheeps milk is easier to digest, if you want to try those. (That said, I am still putting milk in my coffee and eating yogurt! Oh well, easier said than done...)
I've never tried the wheat elimination diet. But if you do a search on the MDC boards I'd bet you'd find a lot of good information on allergies, dairy, wheat, and other potential allergens.
I personally am just "going with the flow" at this point and nursing ds back to sleep whenever he wakes. He sleeps very well as long as he knows I am there.
One other thing I just remembered: someone mentioned that a chiropractor helped their baby with sleep - the baby had a traumatic birth experience and the chiropractic treatment helped to release the stress toxins and aid the baby in more restful sleep.