Is there a reason you need to wean her when she turns 1? Our society has built 1 up to be this magical age when our babies grow up. I think it has a lot to do with doctors OK-ing babies to go from formula to cow's milk at age 1 and to get rid of the bottle. But breasts are so much different than bottles and breast milk is so incredibly healthier than formula or cow's milk! She will still be benefiting from your milk when she is 1. :) Your milk is made perfectly for her whether she is 1 year or 1 week.
A suggestion on weaning is to begin to wean her in the day first. Start with the feedings she seems most content to forgo and be replaced with a sippy cup, snack and smiles from mama. Take it slowly. :) She is still a baby and this all goes by so quickly. A couple great books on the subject are How Weaning Happens and Nursing Mother's Guide to Weaning.
The middle of the night nursings are so very normal. She is most likely becoming very active during the day. Night is time for rest, but she still needs you and to feel secure after a day of exploring. This link offers some great information on a gentle way to wean your baby at night: http://www.drjaygordon.com/development/ap/sleep.asp I did a similar way of night weaning my children except when they were closer to 2. Just don't wean by abandoning her. Make sure she knows you're still there for her, just not at your breast.
You have given your baby such a precious gift by nursing her. I know it is hard work, but parenting is hard work. Whether you nurse or not, she will still need you (help falling asleep, help eating, help being comforted, etc) whether it's at the breast or pacing the halls. My toddlers also nursed during the night and it is not always fun. But neither is listening to them scream. Listen to your heart, to your mama instincts.
I'm sorry this probably isn't the advice you were wanting to hear, but my vote is to wean gradually. :)