D.H.
Hey there,
I weaned both my kids at about 12 months. They both were waking up in the middle of the night to "eat" but they didn't really need the nutrition. It was just a habit, albiet a comforting habit for them. But when I finally weaned them, they stopped waking up in the middle of the night. Funny how that works!
Nutritionally, babies technically don't need breastmilk after they are taking in solids and are drinking cow's milk which is okay to do once they turn 1 year old. So, I think you're okay there. Is she drinking from a sippy cup yet? Before weaning her, I'd try to get her to start drinking from a sippy cup. At about 1 year old, you should start working with her on the sippy. Once she can do that, then you can start giving her regular cow's milk to drink. Yay!
Now, as far as weaning goes, your production is fullest in the wee hours of the morning and it's probably also the fullest around 4:30 pm when you get home from work. It's probably the lowest at the 7:30 pm feeding. So, I'd suggest cutting out the 7:30 pm feeding first. Then after a week or so, cut out the 4:30 pm feeding, then cut out the 7:30 am feeding. Get it down to the point where you are only nursing her one time in the middle of the night feeding. This can be done gradually over the course of a few weeks so you body doesn't produce as much milk.
Last up, the trickiest thing..you'll have to stop the 1:30 am feeding. She won't be happy at all. Neither was my daugther. I used my hubby to help with this. When she woke up and wanted to nurse, HE would go into her and tell her to go back to sleep. She cried and threw a fit the first few nights but when she realized that I wasn't coming in to nurse her, but all she got was old daddy, she actually stopped waking up. Then she began to sleep through the night....at 12 months old. :o) It was heaven! The key to this is to get your husband to do it. She'll know he doesn't have milk for her. But don't offer her a bottle either in the middle of the night. Then, you've just set yourself up for more problems. Have hubby tell her that it's night, she needs to go back to sleep, and see her in the morning. He can't take her out of the crib and rock her to sleep either. He just has to be firm, tell her to lay back down, and then leave the room. She'll cry. My daughter did, but after about a week, she stopped and she finally began sleeping soundly.
One last point: if she isn't on a sippy cup yet or if she is really attached to a bottle, I think it's okay to give her one at 12 months if you are trying to wean her and she's just crabby or needs that comfort of sucking. Just put water or cow's milk in it and don't give her a bottle in the middle of the night! If she is healthy and growing and 12 months old, she does not need to eat at 1:30 am. That is almost a direct quote from my own doctor! LOL Best of luck to you!