Would like to get away from formula - mainly as I'm sick of sterilizing and would be cheaper too 
If you are using a bottle for any kind of milk then *ideally* you should still sterilise. I didn't do it every day at that age, I gave them a good wash and then sterilised once a week or so!
Once they hit 1 they only need about 14oz of dairy to get their needs met and that doesn't have to be liquid milk, all the dairy in food counts. It sounds like her diet at the moment is fine for her age!
We found that at about 13 months my DD began refusing her breakfast so we swapped her milk to a sippy and offered it mid morning with toast as a snack. She didn't drink much at first but after a couple of weeks she got the hang of it and was drinking a whole sippy of cow's milk.
Are you using a fast teat on the bottles? A bottle feed should be done with in about 20 mins - and don't forget that milk is a drink now not a food!
Laura